解方程组xy(x+y)=30 x3+y3=35
问题描述：
解方程组xy(x+y)=30 x3+y3=35
答
(x+y)^3= X^3+3X^2Y+3XY^2+Y^3
x^2y+xy^2=30 3x^2y+3xy^2=90
x^3+Y^3=35