若y-x=-3,xy=28,试求x²y-xy²的值
问题描述:
若y-x=-3,xy=28,试求x²y-xy²的值
答
x²y-xy²
=xy(x-y)
=28*3
=84
若y-x=-3,xy=28,试求x²y-xy²的值
x²y-xy²
=xy(x-y)
=28*3
=84