已知m-n=1,mn=2,求m^3n-2m^2n^2+mn^3的值.
问题描述:
已知m-n=1,mn=2,求m^3n-2m^2n^2+mn^3的值.
答
∵m-n=1,mn=2
∴m^3n-2m^2n^2+mn^3
=mn(m²-2mn+n²)
=mn(m-n)²
=1²×2
=2