按要求解方程配方法: 4x²+14x+2=0因式分解法:x²+5x+4=0 x(x-20)=-514(x-3)²=9(1

1、4x^2+14x+(7/2)^2-49/4+2=0
(2x+7/2)^2=41/4
2、x²+5x+4=0
(x+1)(x+4)=0
3、x(x-20)=-51
x^2-20x+51=0
(x-17)(x-3)=0
4、4(x-3)²=9(1-x)²
[2(x-3)]^2=[3(1-x)]^2
[2(x-3)]^2-[3(1-x)]^2=0
[2(x-3)+3(1-x)][2(x-3)-3(1-x)]=0
(-x-3)(5x-9)=0