x²-2=0x²=2(x-1)²/(x²-1)+x²/(x+1)=(x-1)²/(x+1)(x-1)+x²/(x+1)=(x-1)/(x+1)+x²/(x+1)=(x-1+x²)/(x+1)=(x-1+2)/(x+1)=(x+1)/(x+1)=1