问题 解答题

解方程:

(1)(x+3)2=(1-2x)2

(2)x2+2x-120=0.

答案

(1)(x+3)2=(1-2x)2

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

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

(-x+4)(3x+2)=0,

-x+4=0或3x+2=0,

x1=4,x2=-

2
3

(2)x2+2x-120=0,

(x+12)(x-10)=0,

x+12=0或x-10=0,

x1=-12,x2=10.

单项选择题
单项选择题