有四道题需要用因式分解法解 (1) 4x平方 =81(2) (x-2）平方 –x=0(3) (2x-1)(x-1)=3(

(1) 4x^2 =81
x^2=81/4 x=9/2 或 -9/2
(2) (x-2）^2 –x=0
x^2-4x+4-x=0 x^2-5x+4=0 (x-4)(x-1）=0 x=4 或 x=1
(3) (2x-1)(x-1)=3
2x^2-3x+1-3=0 2x^2-3x-2=0 (2x+1)(x-2）=0 x= -1/2 或 x=2
(4) (x+3)^2 -（2x-3）^2 =0
(x+3-2x+3)(x-1+2x-3）=0 (-x+6)(3x-4）=0 x=6 或 x=3/4