x^-2y^-2÷(x^-2-y^-2)

问题描述:

x^-2y^-2÷(x^-2-y^-2)

解x^-2y^-2÷(x^-2-y^-2)=1/x²y²÷(1/x²-1/y²)=1/x²y²÷(y²-x²)/x²y²=1/x²y²×(x²y²)/(y²-x²)=1/(y²-x²)