用适当方法解下列方程 (1)x2-10x+25=7; (2)(x-1)2+2x(x-1)=0.
问题描述:
用适当方法解下列方程
(1)x2-10x+25=7;
(2)(x-1)2+2x(x-1)=0.
答
(1)x2-10x+25=7,移项得:x2-10x+18=0,b2-4ac=(-10)2-4×1×18=28,∴x=10±282×1,∴x1=5+7,x2=5-7.(2)(x-1)2+2x(x-1)=0,分解因式得:(x-1)(x-1+2x)=0,即x-1=0,x-1+2x=0,解方程得:x1=1,x2=...