一元二次方程~~help~~~~~~因式分解法解~

2x^2-6x=5x-15
2x^2-6x-5x+15=0
2x^2-11x+15=0
(2x-5)(x-3)=0
2x-5=0,x-3=0
x1=2.5,x2=3

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

2x²-6x=5x-15
2x²-6x-5x+15=0
2x²-11x+15=0
(x-3)(2x-5)=0
所以 x=3 或 x=2.5

(2x-1)(x+1)=(3x+1)(x+1)
(2x-1)(x+1)-(3x+1)(x+1)=0
(x+1)[2x-1-(3x+1)]=0
(x+1)(-x-2)=0
(x+1)(x+2)=0
所以 x=-1或x=-2