4(x方+y)(x方-y)-(2x方-y)方,其中x=2,y=-3

问题描述:

4(x方+y)(x方-y)-(2x方-y)方,其中x=2,y=-3

4(x²+y)(x²-y)-(2x²-y)² =4(x⁴-y²)-(2x²-y)²=4(x⁴-y²)-(4x⁴-4x²y+y²)=4x⁴-4y²-4x⁴+4x²y-y²=4x...