7、用因式分解法解下列方程:
(1)(x+3)2=2x+6
解:(x+3)(x+3-2)=0
x1=-3, x2=-1
(2)2(5x-1)2=3(1-5x)
解:(5x-1)(10x-2+3)=0
x1= , x2=
(3)9(x-2)2=4(x+1)2
解:[3(x-2)+2(x+1)][3(x-2)-2(x+1)]=0
(5x-4)(x-8)=0
x1= , x2=8
(4)(2x-1)2-x2-4x-4=0
解:(2x-1)2-(x+2)2=0
(2x-1+x+2)(2x-1-x-2)=0
(3x+1)(x-3)=0
x1= ,x2=3 |