(for help, go to lessons 1-4, 1-5 and 1-6) algebra 1 lesson 2-1 simplify each expression. 1. x – 2...

(For help, go to Lessons 1-4, 1-5 and 1-6)

ALGEBRA 1 LESSON 2-1ALGEBRA 1 LESSON 2-1

Simplify each expression.

1. x – 2 + 2 2. n + 2 – 2 3. • 5 4.

For each number, state its opposite and its reciprocal.

5. 2 6. –2 7. 8. –

7m7

c5

35

35

Solving One-Step EquationsSolving One-Step Equations

2-1

Solutions

1. x – 2 + 2 = x + 0 = x

2. n + 2 – 2 = n + 0 = n

3. • 5 = c • = c • 1 = c

4. = • m = 1 • m = m

c5

55

7m7

77

5. opposite of 2 is –2; reciprocal of 2 is 12

6. opposite of –2 is 2; reciprocal of –2 is – 12

7. opposite of is – ; reciprocal of is 35

35

35

53

8. opposite of – is ; reciprocal of – is – 35

35

35

53

Solving One-Step EquationsSolving One-Step EquationsALGEBRA 1 LESSON 2-1ALGEBRA 1 LESSON 2-1

2-1

Solve b – 5 = 7.

b – 5 + 5 = 7 + 5 Add 5 to each side to get the variable alone on the left side of the equal sign.b = 12 Simplify.

Check: b – 5 = 12 Check your solution in the original equation.

12 – 5 7 Substitute 12 for b.

7 = 7


2-1

Find the value of a.

PQ = PR

11 = 6 + a The lengths of congruent sides are equal.

5 = a Simplify.

The value of a is 5.

11 – 6 = 6 + a – 6 Subtract 6 from each side.

Check: 11 = 6 + a Check your solution in the original equation.

11 6 + 5 Substitute 5 for a.11 = 11


2-1

Together, you and your puppy weigh 128 lb. If you alone

weigh 115 lb, how much does your puppy weigh?

115 + p = 128

115 + p – 115 = 128 – 115 Subtract 115 from each side.p = 13 Simplify.

The puppy weighs 13 lb.

Check: Is the solution reasonable? The puppy weighs about 15 lb. The puppy’s weight plus your weight is about 130 lb, which is close to 128 lb. The answer is reasonable.

Relate: your weight plus puppy’s weight equals combined weight

Define: Let p = the puppy’s weight.

Write: 115 + p = 128


2-1

Solve – = –9.3t6

t = 55.8 Simplify.


2-1

– 6 (– ) = – 6(9.3) Multiply by –6 on each side to get the variable alone on the left side of the equal sign.

t6

Solve y = –1025

y = –25 Simplify.


2-1

( )y = (–10) Multiply each side by , the reciprocal of .

25

52

52

52

25

Check: y = –1025

(–25) –10 Substitute –25 for y.

25

–10 = –10

Solve –6m = 42.

m = –7 Simplify.

= Divide each side by –6. –6m –6

42 –6


2-1

Solve each equation.

1. b – 8 = –2 2. –12 = x + 9 3. – = 14

4. 28 = x 5. 12r = –7245

y76 –21 –98

35 –6


2-1

(For help, go to Lessons 2-1.)


Solve each equation and tell which property of equality you used.

1. x – 5 = 14 2. x + 3.8 = 9 3. –7 + x = 7

4. x – 13 = 20 5. = 8 6. 9 = 3x


7. 10x = 2 8. x = –6 9. x + 2 = 623

x4

34

12

Solving Two-Step EquationsSolving Two-Step Equations

2-2

Solutions

Solving Two-Step EquationsSolving Two-Step EquationsALGEBRA 1 LESSON 2-2ALGEBRA 1 LESSON 2-2

15

1. x – 5 = 14x – 5 + 5 = 14 + 5 Addition Property

x = 19 of Equality

2. x + 3.8 = 9x + 3.8 – 3.8 = 9 – 3.8 Subtraction Property

x = 5.2 of Equality

3. –7 + x = 7 –7 + x + 7 = 7 + 7 Addition Property

x = 14 of Equality

4. x – 13 = 20x – 13 + 13 = 20 + 13 Addition Property

x = 33 of Equation

5. = 8

• 4 = 8 • 4 Multiplication Property

x = 32 of Equality

x4

x4

6. 9 = 3x

= Division Property

3 = x of Equality

3x3

93

7. 10x = 2

=

x =

2 10

10x10

2-2

Solutions (continued)

8. x = –6

• x = • –6

x = –9

23

23

32

32

9. x + 2 = 6

x + 2 – 2 = 6 – 2

x = 3

34

12

34

34

34

12

34


2-2

Solve 13 = + 5.y3

24 = y Simplify.


2-2

13 – 5 = + 5 – 5 Subtract 5 from each side.y3

8 = Simplify.y3

3 • 8 = 3 • Multiply each side by 3.y3

Check: 13 = + 5y3

13 + 5 Substitute 24 for y.243

13 8 + 5

13 = 13

You order iris bulbs from a catalog. Iris bulbs cost $.90

each. The shipping charge is $2.50. If you have $18.50 to spend,

how many iris bulbs can you order?

Relate: cost per iris times number of iris bulbs plus shipping equals amount to spend.

Define: Let b = the number of bulbs you order.

Write: 0.90 • b + 2.50 = 18.50

0.90b + 2.50 = 18.50

0.90b + 2.50 – 2.50 = 18.50 – 2.50 Subtract 2.50 from each side.

0.90b = 16 Simplify.


2-2

You can order 17 bulbs.

b = 17.7

0.90b0.90 =

160.90 Divide each side by 0.90.

Simplify.


2-2

(continued)

Check: Is the solution reasonable? You can only order whole iris bulbs. Since 18 bulbs would cost 18 • 0.90 = 16.20 plus $2.50 for shipping, which is more than $18.50, you can only order 17 bulbs.

Solve 21 = –p + 8

21 – 8 = –p + 8 – 8 Subtract 8 from each side.

13 = –p Simplify.

–1(13) = –1(–p) Use the Multiplication Propertyof Equality. Multiply each side by –1.

–13 = p Simplify.

Check: 21 = –p + 8

21 –(–13) + 8 Substitute –13 for p.

21 = 21 Simplify.


2-2

Solve 8 = – + 4. Justify each step.

–96 = c Simplify.

c24


2-2

8 – 4 = – + 4 – 4 Subtraction Property of Equalityc

24

4 = – Simplify.c

24

–24(4) = (–24)(– ) Multiplication Propertyof Equality

c24

Solve 3 – 5z = 18. Justify each step.

3 – 5z – 3 = 18 – 3 Subtraction Property of Equality

–5z = 15 Simplify.

z = –3 Simplify.


2-2

= Division Property of Equality –5z–5

15–5


1. 3b + 8 = –10 2. –12 = –3x – 9

3. – + 7 = 14 4. –x – 13 = 35

5. What is the justification for the following step?

12 – 2y = 46

12 – 2y – 12 = 46 – 12

c4

–6 1

–28 –48

Subtraction Property of Equality


2-2

(For help, go to Lessons 1-2 and 1-7.)


Simplify each expression.

1. 2n – 3n 2. –4 + 3b + 2 + 5b

3. 9(w – 5) 4. –10(b – 12)

5. 3(–x + 4) 6. 5(6 – w)

Evaluate each expression.

7. 28 – a + 4a for a = 5 8. 8 + x – 7x for x = –3

9. (8n + 1)3 for n = –2 10.–(17 + 3y) for y = 6

Solving Multi-Step EquationsSolving Multi-Step Equations

2-3

Solutions

1. 2n – 3n = (2 – 3)n = –1n = –n

2. –4 + 3b + 2 + 5b = (3 + 5)b + (–4 + 2) = 8b – 2

3. 9(w – 5) = 9w – 9(5) = 9w – 45

4. –10(b – 12) = –10b – (–10)(12) = –10b + 120

5. 3(–x + 4) = 3(–x) + 3(4) = –3x + 12

6. 5(6 – w) = 5(6) – 5w = 30 – 5w

7. 28 – a + 4a for a = 5: 28 – 5 + 4(5) = 28 – 5 + 20 = 23 + 20 = 43

8. 8 + x – 7x for x = –3: 8 + (–3) – 7(–3) = 8 + (–3) + 21 = 5 + 21 = 26

9. (8n + 1)3 for n = –2: (8(–2) + 1)3 = (–16 + 1)3 = (–15)3 = –45

10. –(17 + 3y) for y = 6: –(17 + 3(6)) = –(17 + 18) = –35

Solving Multi-Step EquationsSolving Multi-Step EquationsALGEBRA 1 LESSON 2-3ALGEBRA 1 LESSON 2-3

2-3

Solve 3a + 6 + a = 90

4a + 6 = 90 Combine like terms.

4a + 6 – 6 = 90 – 6 Subtract 6 from each side.

4a = 84 Simplify.

3a + 6 + a = 90Check:

3(21) + 6 + 21 90 Substitute 21 for a.

63 + 6 + 21 90

90 = 90


2-3

= Divide each side by 4.

a = 21 Simplify.

4a4

844

You need to build a rectangular pen in your back yard for

your dog. One side of the pen will be against the house. Two sides of

the pen have a length of x ft and the width will be 25 ft. What is the

greatest length the pen can be if you have 63 ft of fencing?

Relate: length plus 25 ft plus length equals amount of side of side of fencing

Define: Let x = length of a side adjacent to the house.

Write: x + 25 + x = 63


2-3

x + 25 + x = 63

The pen can be 19 ft long.

2x + 25 = 63 Combine like terms.

2x + 25 – 25 = 63 – 25 Subtract 25 from each side.

2x = 38 Simplify.

x = 19


2-3

(continued)

= Divide each side by 2. 2x2

382

Solve 2(x – 3) = 8

2x – 6 = 8 Use the Distributive Property.

2x – 6 + 6 = 8 + 6 Add 6 to each side.

2x = 14 Simplify.

x = 7 Simplify.


2-3

= Divide each side by 2. 2x2

142

Solve + = 173x2

x5

x = 10 Simplify.


2-3

Method 1: Finding common denominators

+ = 173x2

x5

x + x = 17 Rewrite the equation.32

15

x = 17 Combine like terms. 1710

( x) = (17) Multiply each each by the reciprocalof , which is .

1710

1017

1017 17

101017

x + x = 17 A common denominator of and is 10.

1510

210

32

15

Solve + = 173x2

x5

15x + 2x = 170 Multiply.

17x = 170 Combine like terms.

x = 10 Simplify.


2-3

Method 2: Multiplying to clear fractions

+ = 173x2

x5

10( + ) = 10(17) Multiply each side by 10, a commonmultiple of 2 and 5.

3x2

x5

10( ) + 10( ) = 10(17) Use the Distributive Property.3x2

x5

= Divide each side by 17.17x17

17017

Solve 0.6a + 18.65 = 22.85.

100(0.6a + 18.65)

=

100(22.85)

The greatest of decimal places is two places. Multiply each side by 100.

100(0.6a) + 100(18.65)

=

100(22.85)

Use the Distributive Property.

60a + 1865

=

2285

Simplify.

60a + 1865 – 1865 =2285 – 1865Subtract 1865 from each side.60a =420 Simplify.


2-3

=Divide each side by 60.

60a60

42060

a = 7Simplify.


1. 4a + 3 – a = 24 2. –3(x – 5) = 66

3. + = 7 4. 0.05x + 24.65 = 27.5n3

n4

7 –17

12 57


2-3


Simplify.

1. 6x – 2x 2. 2x – 6x 3. 5x – 5x 4. –5x + 5x


5. 4x + 3 = –5 6. –x + 7 = 12

7. 2t – 8t + 1 = 43 8. 0 = –7n + 4 – 5n

Equations with Variables on Both SidesEquations with Variables on Both SidesALGEBRA 1 LESSON 2-4ALGEBRA 1 LESSON 2-4

2-4

Solutions

1. 6x – 2x = (6 – 2)x = 4x 2. 2x – 6x = (2 – 6)x = –4x

3. 5x – 5x = (5 – 5)x = 0x = 0 4. –5x + 5x = (–5 + 5)x = 0x = 0

5. 4x + 3 = –5 6. –x + 7 = 124x = –8 –x = 5x = –2 x = –5

7. 2t – 8t + 1 = 43 8. 0 = –7n + 4 – 5n–6t + 1 = 43 0 = –12n + 4

–6t = 42 12n = 4 t = –7 n = 1

3


2-4

The measure of an angle is (5x – 3)°. Its vertical angle has a

measure of (2x + 12)°. Find the value of x.

5x – 3 = 2x + 12Vertical angles are congruent.5x – 3 – 2x = 2x + 12 – 2xSubtract 2x from each side.3x – 3 = 12Combine like terms.3x – 3 + 3 = 12 + 3Add 3 to each side.

3x = 15Simplify.


2-4


3x3

153

x = 5 Simplify.

You can buy a skateboard for $60 from a friend and rent the

safety equipment for $1.50 per hour. Or you can rent all items you

need for $5.50 per hour. How many hours must you use a

skateboard to justify buying your friend’s skateboard?

Relate: cost of plus equipment equals skateboard and equipment friend’s rental rental skateboard

Define: let h = the number of hours you must skateboard

Write: 60 + 1.5 h = 5.5 h


2-4

60 + 1.5h = 5.5h

60 + 1.5h – 1.5h = 5.5h – 1.5hSubtract 1.5h from each side.60 = 4hCombine like terms.

You must use your skateboard for more than 15 hours to justify buying the skateboard.


2-4

(continued)

604

4h4 = Divide

each side by 4.15 = h Simplify.


a. –6z + 8 = z + 10 – 7z

–6z + 8 = z + 10 – 7z

–6z + 8 = –6z + 10Combine like terms.–6z + 8 + 6z = –6z + 10 + 6zAdd 6z to each side.8 = 10Not true for any value of z!This equation has no solution


b. 4 – 4y = –2(2y – 2)

The equation is true for every value of y, so the equation is an identity.

4 – 4y = –2(2y – 2)

4 – 4y = –4y + 4Use the Distributive Property.4 – 4y + 4y = –4y + 4 + 4yAdd 4y to each side.4 = 4 Always true!

2-4


1. 3 – 2t = 7t + 4 2. 4n = 2(n + 1) + 3(n –

1)

3. 3(1 – 2x) = 4 – 6x

4. You work for a delivery service. With Plan A, you can earn $5 per hour plus $.75 per delivery. With Plan B, you can earn $7 per hour plus $.25 per delivery. How many deliveries must you make per hour with Plan A to earn as much as with Plan B?

4 deliveries

1

no solution


2-4

– 19

(For help, go to Lesson 1-1.)


Write a variable expression for each situation.

1. value in cents of q quarters

2. twice the length

3. number of miles traveled at 34 mi/h in h hours

4. weight of 5 crates if each crate weighs x kilograms

5. cost of n items at $3.99 per item

Equations and Problem SolvingEquations and Problem Solving

2-5

Solutions

1. value in cents of q quarters: 25q

2. twice the length : 2

3. number of miles traveled at 34 mi/h in h hours: 34h

4. weight of 5 crates if each crate weighs x kilograms: 5x

5. cost of n items at $3.99 per item: 3.99n

Equations and Problem SolvingEquations and Problem SolvingALGEBRA 1 LESSON 2-5ALGEBRA 1 LESSON 2-5

2-5

The width of a rectangle is 3 in. less than its length. The

perimeter of the rectangle is 26 in. What is the width of the

rectangle?

Relate: The width is 3 in. less than the length.

Then x – 3 = the width.

Define: Let x = the length. The width is described in terms of the length. So define a variable for the length first.

Write: P = 2 + 2w Use the perimeter formula.26 = 2 x + 2( x – 3 ) Substitute 26 for P, x for , and x – 3 for w.


2-5

26 = 2x + 2x – 6 Use the Distributive Property.26 = 4x – 6 Combine like terms.26 + 6 = 4x – 6 + 6 Add 6 to each side.32 = 4x Simplify.

The width of the rectangle is 3 in. less than the length, which is 8 in. So the width of the rectangle is 5 in.


2-5

(continued)

= Divide each side by 4.8 = x Simplify.

324

4x4

The sum of three consecutive integers is 72. Find the integers.

Relate: first plus second plus third is 72 integer integer integer

Define: Let x = the first integer.

Then x + 1 = the second integer,

and x + 2 = the third integer.

Write: x + x + 1 + x + 2 = 72


2-5

If x = 23, then x + 1 = 24, and x + 2 = 25. The three integers are 23, 24, and 25.

x + x + 1 + x + 2 = 72

3x + 3 = 72Combine like terms. 3x + 3 – 3 = 72 – 3Subtract 3 from each side. 3x = 69

Simplify.


2-5

(continued)


3x3

693

x = 23Simplify.

An airplane left an airport flying at 180 mi/h. A jet that flies at

330 mi/h left 1 hour later. The jet follows the same route as the

airplane on parallel altitudes. How many hours will it take the jet to

catch up with the airplane?

Aircraft Rate Time Distance Traveled

Airplane 180 t 180t

Jet 330 t – 1 330(t – 1)

Define: Let t = the time the airplane travels.

Then t – 1 = the time the jet travels.


2-5

Relate: distance traveled equals distance traveledby airplane by jet

Write: 180 t = 330( t – 1 )

180t = 330(t – 1)180t = 330t – 330 Use the Distributive Property.

180t – 330t = 330t – 330 – 330t Subtract 330t from each side.

–150t = –330 Combine like terms.


2-5

(continued)

= Divide each side by –150.–150t–150

–330–150

t = 2 Simplify.15

t – 1 = 1 15

The jet will catch up with the airplane in 1 h.15

Suppose you hike up a hill at 4 km/h. You hike back down at

6 km/h. Your hiking trip took 3 hours. How long was your trip up the

hill?

Define: Let x = time of trip uphill.

Then 3 – x = time of trip downhill.

Relate: distance uphill equals distance downhill

Part of hike Rate Time Distance hiked

Uphill 4 x 4x

Downhill 6 3 – x 6(3 – x)

Write: 4 x = 6( 3 – x )


2-5

4x = 6(3 – x)

4x = 18 – 6x Use the Distributive Property.

4x + 6x = 18 – 6x + 6x Add 6x to each side.

10x = 18 Combine like terms.


2-5

(continued)


1810

x = 1 Simplify.45

Your trip uphill was 1 h long.45

Two jets leave Dallas at the same time and fly in opposite

directions. One is flying west 50 mi/h faster than the other. After

2 hours, they are 2500 miles apart. Find the speed of each jet.

Define: Let x = the speed of the jet flying east.

Write: 2 x + 2( x + 50 ) = 2500

Then x + 50 = the speed of the jet flying west.

Relate: eastbound jet’s plus westbound jet’s equals the total distance distance distance

Jet Rate Time Distance Traveled

Eastbound x 2 2x

Westbound x + 50 2 2(x + 50)


2-5

2x + 2(x + 50) = 2500

2x + 2x + 100 = 2500 Use the Distributive Property.

4x + 100 = 2500 Combine like terms.

4x + 100 – 100 = 2500 – 100 Subtract 100 from each side.4x = 2400 Simplify.

x = 600

x + 50 = 650

The jet flying east is flying at 600 mi/h. The jet flying west is flying at 650 mi/h.


2-5

(continued)


24004

1. The sum of three consecutive integers is 117. Find the integers.

2. You and your brother started biking at noon from places that are 52 mi apart. You rode toward each other and met at 2:00 p.m. Your brother’s average speed was 4 mi/h faster than your average speed. Find both speeds.

3. Joan ran from her home to the lake at 8 mi/h. She ran back home at 6 mi/h. Her total running time was 32 minutes. How much time did it take Joan to run from her home to the lake?

38, 39, 40

your speed: 11 mi/h; brother’s speed: 15 mi/h

about 13.7 minutes


2-5

(For help, go to Lessons 1-2, 1-4 and 1-6.)

Evaluate each formula for the values given.

1. distance: d = rt, when r = 60 mi/h and t = 3 h

2. perimeter of a rectangle: P = 2 + 2w, when = 11 cm, and w = 5 cm

3. area of a triangle: A = bh, when b = 8 m and h = 7 m12

FormulasFormulasALGEBRA 1 LESSON 2-6ALGEBRA 1 LESSON 2-6

2-6

Solutions

1. d = rt = 60(3) = 180 mi

2. P = 2 + 2w = 2(11) + 2(5) = 22 + 10 = 32 cm

3. A = bh = (8)(7) = 4(7) = 28 m212

12


2-6

Solve the formula for the volume of a rectangular prism

V = wh for width w in terms of its volume V, length , and its

height h.

V = wh

= wh Simplify.V


2-6

= Divide each side by , = 0.V wh

/

= Divide each side by h, h = 0, to get w alone on one side of the equation.

V h

wh h /

= w Simplify. V h

Solve y = 4x – 3 for x.

y + 3 = 4x – 3 + 3 Add 3 to each side.

y + 3 = 4x Simplify.


2-6

= Divide each side by 4.y + 3

44x4

= x Simplify.y + 3

4

Solve z – br = p for b in terms of z, r, and p.

z – br – z = p – z Subtract z from each side.

–br = p – z Combine like terms.


2-6

= Divide each side by –r.–br–r

p – z–r

b = – Simplify.p – z–r

The formula K = C + 273.15 gives the Kelvin temperature K

in terms of the Celsius temperature C. Transform the formula to find

Celsius temperature in terms of Kelvin temperature. Then, find the

Celsius temperature when the Kelvin temperature is 400°.

Solve for C.

K = C + 273.15

K – 273.15 = C + 273.15 – 273.15 Subtract 273.15 from each side.

K – 273.15 = C Simplify.

Find C when K = 400.

400 – 273.15 = C Substitute 400 for K.

126.85 = C

400º K is 126.85º C.


2-6

Solve each equation for the given variable.

1. 3x + 2y = z; y 2. = ; a

3. 3x + 4 = 2(3 – y); y

4. The formula v2 = can be used to find the constant speed v

of a satellite revolving around Earth in a circular orbit of radius r. G is

a number known as the gravitational constant and M is the mass of

Earth. Transform this formula to find the mass of Earth.

a – bc

d3

GMr

M = v2rG


2-6

a = + bcd3y = z – x1

232

y = – x + 132


Write the numbers in each group in order from least to greatest.

1. 2.4, 9.8, 3.6, 7.5, 1.92. 144, 235, 98, 72, 58, 195

3. –12, 14, –3, –8, 7, 0 4. 2 , –3 , –4 , 6 , –2 , 4

Use mental math to simplify.

5. 6.3 + 4 + 5 + 6 + 75

5 + 6 + 8 + 94

12

23

38

14

58

12

Using Measures of Central TendencyUsing Measures of Central TendencyALGEBRA 1 LESSON 2-7ALGEBRA 1 LESSON 2-7

2-7

Solutions

1. 1.9, 2.4, 3.6, 7.5, 9.8

2. 58, 72, 98, 144, 195, 235

3. –12, –8, –3, 0, 7, 14

4. –4 , –3 , –2 , 2 , 4 , 6

5. = = 5

6. = = 7

38

23

58

12

12

14

3 + 4 + 5 + 6 + 75

255

5 + 6 + 8 + 94

284


2-7

Find the mean, median, and mode of the data below.

Determine which measure of central tendency best describes

the data.14 10 2 13 16 3 12 11

Mode: none The data item that occurs most often.

The mean is 10.125, the median is 11.5, and there is no mode. The mean is less than 5 of the 8 data items because of the outliers 2 and 3. The median best describes the data.

Mean: 14 + 10 + 2 + 13 + 16 + 3 + 12 + 118

= 10.125total number of data items


2-7

Median: 2 3 10 11 12 13 14 16 List data in order.

= 11.5 For an even number of data items,find the mean of the two middle terms.

11 + 122

82 + 94 + 89 + x

4Mean (average): = 90

Let x = the grade of the fourth exam.

Suppose your grades on three science exams are 82, 94,

and 89. What grade do you need on your next exam to have an

average of 90?

265 + x

4= 90 Simplify the numerator.

4( ) = 4(90) Multiply each side by 4.265 + x

4

265 + x = 360 Simplify.


2-7

(continued)

265 + x – 265 = 360 – 265 Subtract 265 from each side.

x = 95 Simplify.

Your grade on the next exam must be 95 for you to have an average of 90.


2-7

Find the range and mean of each set of data. Use the range

to compare the spread of the two sets of data.

45 47 34 36 38 56 35 27 47 35

Range: 47 – 34 = 13 Range: 56 – 27 = 29

Both sets have a mean of 40. The range of the first set of data is 13 and the range of the second set of data is 29. The first set of data clusters nearer the mean.


2-7

Mean: 45 + 47 + 34 + 36 + 385

= 2005

= 40

Mean: 56+ 35 + 27 + 47 + 355

= 2005

= 40

Make a stem-and-leaf plot for the data.

56 44 63 58 51 59 47 51 67 50 65 49 66 63

5|1 means 51


2-7

Find the mean of the city mileage and the mean of the

highway mileage.

4|2 means 42

Mean City Mileage:17 + 18 + 20 + 21 + 24 + 26 + 36 + 38

8 = 25 mi/gal

Mean Highway Mileage:22 + 24 + 30 +30 + 32 + 33 + 38 + 43

8 = 31.5 mi/gal


2-7

1. Find the mean, median, and mode. Which measure of central tendency best describes the data? 49 52 53 56 62 61 55 52

2. Make a stem-and-leaf plot for the data above.

3. Your test grades are 83, 94, 86, and 91. What grade do you need to earn on your next test to have an average of 90?

mean 55; median 54; mode 52; The mean best describes the data.

4|9 means 49

96


2-7

(for help, go to lessons 1-4, 1-5 and 1-6) algebra 1 lesson 2-1 simplify each expression. 1. x – 2...

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