仅供参考解方程x2-1=0(x+1)(x-1)=0x+1=0x-1=0x1=-1x2=1
解：x的平方-1=0x²-1=0x²=1x=+1 或-1
x²-1=0(x+1)(x-1)=0x+1=0,x-1=0x1=-1,x2=1
x ²-1=0(x +1)(x -1)=0x +1=0 x= -1x -1=0 x= 1
