8x²（2x²-y²）+y四次方=16x的4次方-8x²y²+y的4次方=（4x²-y²）²=(2x+y)²(2x-y)²（x²+x）²-（x+1）²=(x²+x+x+1)(x²+x-x-1)=(x+1)²...