用因式分解法解下列方程5x²-20x+20=0（x+5）²=3x+15（2x-1）²=（3-x）²5x²-2x-1/4=x²-2x+3/43x²-12x=-12

Question

用因式分解法解下列方程
5x²-20x+20=0 （x+5）²=3x+15 （2x-1）²=（3-x）² 5x²-2x-1/4=x²-2x+3/4 3x²-12x=-12

Answer 1

(1) 5（x-2）²=0,x=2
(2)x²+10x+25=3x+15
x²+7x+10=0
(x+2)(x+5)=0,x1=-2,x2=-5
(3)4x²-4x+1=9-6x+x²
3x²+2x-8=0
(3x-4)(x+2)=0 ,x1=4/3,x2=-2
(4)4x²-1=0
(2x+1)(2x-1)=0
x1=-1/2,x2=1/2
(5)3(x²-4x+4)=0
3(x-2)²=0 ,x=2