已知实数a,b满足ab=-1/5,a+b=4/5,求a^2b+ab^2-a^3b^2-a^2b^3
问题描述：
已知实数a,b满足ab=-1/5,a+b=4/5,求a^2b+ab^2-a^3b^2-a^2b^3
答
解
a²b+ab²-a³b²-a²b³
=ab(a+b)-(ab)²(a+b)
=-1/5×(4/5)-(-1/5)²×(4/5)
=-4/25-4/125
=-24/125