,已知x+y=-3,xy=-1又2分之1,求代数式(x^3y+xy^3)/(-xy)的值
问题描述:
,已知x+y=-3,xy=-1又2分之1,求代数式(x^3y+xy^3)/(-xy)的值
答
原式=xy(x²+y²)/(-xy)=-(x²+y²)=-(x+y)²+2xy=-9-3=-12
,已知x+y=-3,xy=-1又2分之1,求代数式(x^3y+xy^3)/(-xy)的值
原式=xy(x²+y²)/(-xy)=-(x²+y²)=-(x+y)²+2xy=-9-3=-12