(x²y³+xy)(x²y³-xy)÷x²y³,其中x=3,y=2
问题描述：
(x²y³+xy)(x²y³-xy)÷x²y³,其中x=3,y=2
答
(x²y³+xy)(x²y³-xy)÷x²y³
=(x^4y^6-x²y²)÷x²y³
=x²y³-1/y
带入 x=3 y=2得
=9×8-1/2
=71.5