Chng 3: Phng trnh v h phng trnhA. Phng trnh.I. Kin thc cn nm.1) Phng trnh cha cn

hoc

2) Phng trnh cha du gi tr tuyt i

hoc

3) Cc phng php c bn khi gii phng trnha) Bin i a v dng c bn (quy ng, rt gn, bnh phng,)b) t n ph: Chn mt biu thc lm n ph, t iu kin cho n ph. Quy phng trnh cho v phng trnh n ph v gii phng trnh theo n ph. Tr v n x v gii tm x.c) S dng lng lin hp:

II. Bi tp1) Tm KX v gii cc phng trnh sau:

2) Tm tham s m sao cho hai phng trnh sau l tng ng.

a) v

b) v

c) v 3) Gii cc phng trnh cha cn sau bng cch a v dng c bn.

4) Gii cc phng trnh cha du gi tr tuyt i sau bng cch a v dng c bn.

5) Gii cc phng trnh sau bng cch t n ph.

6) Gii cc phng trnh sau bng cch s dng lng lin hp.

7) Gii cc phng trnh sau.