Question

解下列方程（用因式分解法求解一元二次方程）1、5（x^2-x)=3(x^2+x) 2、(x-

Answer 1

1. 5x(x-1)-3x(x+1)=0

x[5(x-1)-3(x+1)]=0

x(2x-8)=0

x=0, 4

2. (x-2)^2-(2x+3)^2=0

(x-2+2x+3)(x-2-2x-3)=0

(3x+1)(-x-5)=0

x=-1/3, -5

3. x^2-5x+6=12

x^2-5x-6=0

(x-6)(x+1)=0

x=6 , -1

4. x^2+6x+9-2x-6=0

x^2+4x+3=0

(x+1)(x+3)=0

x=-1, -3

5. 2y^2+3y-2=0

(2y-1)(y+2)=0

y=1/2, -2