用因式分解法解下列方程: (1)(4x-1)(5x+7)=0. (2)3x(x-1)=2-2x. (3)(2x+3)2=4(2x+3). (4)2(x-3)2=x2-9.

问题描述:

用因式分解法解下列方程:
(1)(4x-1)(5x+7)=0.
(2)3x(x-1)=2-2x.
(3)(2x+3)2=4(2x+3).
(4)2(x-3)2=x2-9.

(1))(4x-1)(5x+7)=0,
4x-1=0,5x+7=0,
x1=

1
4
,x2=-
7
5

(2)3x(x-1)=2-2x,
3x(x-1)+2(x-1)=0,
(x-1)(3x+2)=0,
x-1=0,3x+2=0,
x1=1,x2=-
2
3

(3)(2x+3)2=4(2x+3),
(2x+3)2-4(2x+3)=0,
(2x+3)(2x+3-4)=0,
2x+3=0,2x+3-4=0,
x1=-
3
2
,x2=
1
2

(4)2(x-3)2=x2-9,
2(x-3)2-(x+3)(x-3)=0,
(x-3)[2(x-3)-(x+3)]=0,
x-3=0,2(x-3)-(x+3)=0,
x1=3,x2=9.