5x(x-3)-(x-3)(x+1)=0 用因式分解法解?

问题描述:

5x(x-3)-(x-3)(x+1)=0 用因式分解法解?

答:
提取公因式x-3:
5x(x-3)-(x-3)(x+1)=0
(x-3)(5x-x-1)=0
(x-3)(4x-1)=0
解得:x1=3,x2=1/4

(X-3)(5X-X-1)=0 (X-3)(4X-1)=0 故X=3 或者X=1/4