x²+2x+1=4.X怎么解

问题描述:

x²+2x+1=4.X怎么解

x²+2x+1=4
x²+2x-3=0
(x+3)(x-1)=0
x=-3或x=1(x+1)(x+2)=0呢?(x+1)(x+2)=0x=-1或 x=-2