用因式分解法解2(x-1)^2-3(x-1)-9=0

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用因式分解法解2(x-1)^2-3(x-1)-9=0

用因式分解法解2(x-1)^2-3(x-1)-9=0
用因式分解法解2(x-1)^2-3(x-1)-9=0

用因式分解法解2(x-1)^2-3(x-1)-9=0
(2(x-1)+3)((x-1)-3)=0
(2x+1)(x-4)=0
解得:x=- 1/2,x=4

2(x-1)^2-3(x-1)-9=0
[2(x-1)+3][(x-1)-3]=0---------------十字相乘法
(2x+1)(x-4)=0
x=-0.5或者4

2(x-1)^2-3(x-1)-9=(x-1)^2-9+(x-1)^2-3(x-1)=(x-1-3)(x-1+3)+(x-1)(x-1-3)=(x-4)(x+2)+(x-1)(x-4)
=(x-4)(2x+1)=0
所以x1=4 x2=-1/2
所以解为4和-1/2

(2(x-1)+3)((x-1)-3)=0
(2x+1)(x-4)=0
解得:x=- 1/2,x=4