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BC = 8>/2 3 AB = AC = 8 £*>• lilio ABC j£J -1
A .̂gà ^3'j" f^l* ABC u^Jt** !̂ b^ O^
BF = x j^îCJ 3 B 3 A J &îbw [ AB] ̂ F 4tûj j*a« -2
gj (BC) <jfcwi (AB) ̂ 4.5̂ 3*̂ 13 F O* JW' (0*&^«Jt
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= X Ù* 0*̂ "
g= x ( 8 x )AEF
8 J AEF
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0 < a < 8
x
F 5JbflUf 9̂3* <3Jbs)f eJJb
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* 60
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[80 ; 100[
20
[60 ; 80[
60
[40 ; 60[
210
[20 ; 40[
490
[0 ; 20[
220
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A — O i ^ , ^
A£ A du (PGCD(2,7) = \)
.J-"''"'•" J& 4jaSJffl
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\fl.iill , "jjjollj -^A **-.-*>* -^l*Wl J | 2012 ùL^
b = 7 + 4^/3 ja = 7-4^/3 :ùàAb jj>Jlt-jJL» eA a
a b 2 , 2-+ — = a2 + bb a 7- W3) = (7)2 - (4V3)
= 97 + 56VJ+ 97 - 56
= 4^-16x3 = 49-48 =j cr il,
42 x 7x +
16^3 = 97+ 56^3
= (7)2-2x7,,x
= 49-56^3+ 16* 3 = 97- 56^3X ..^..v
. /BM = <
MD = Jîî JBD = 5^/2 J M e [BD]
BM = BD- MD BD = BM + MD :ûiBM = 5V2 - VÊ = 5 V2 -
BM MD BM + MD
MD = «Je JBM = JÏ8BM MD . .
MD = -BD JBM -5
5 Jj [BD] f 3 2
BM JÎ8[BD 1 Û* M
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A ̂ Ljljlt ffâ ABCBC2 = (8>/2)2 =82x(V2)2 =64x2 = 128
ABC LÎJÎiJlC' LjJJ
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AC = 8v/2
AC = 8
(AC)I/(EF)û4'(AB)±ÏAty j (AB) 1
[BC] ù* U** E j [AB] ù* -ÏLtfA ABC&(màjJ/(AC)//(EF)j
BE EK BF BE EFBA = 8
EF = X\ ^
BC ACx EF
^J FBE = 45° <*j ABC * ACB = 45° fyA J j= EBF = 45° ^Jpf990° - EBF = 90°- 45° -45° ù
EF = x F
a = EFxFA
\ EF- x
/ « _i O C* — O
: J& (1.3_ 42-2x4xx + x2 = (4-x)2
2 2 20 < a < 8 ÙÎ&&*} (V
F • • l J Fe[AB]j B F = - B A <^J
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JÏ l-«-''-«l
.1y/ UuiLJl eJjJ ^ylaaJ/ J/J&L ^^.y ̂ 1 IJA
= 220+490+210+60+20=1000
[80,100[
20
90
[60,80[
60
70
[40,60[
210
50
[20,40[
490
30
[0,20[
220
10
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220x10 + 490x30 + 210x50 + 210x5 d*V6 0 x 70\+ 20 x90.
.
10 20 M(3CL 31 34 40
220 + 490 + 2 1 0 .J .3
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