若x-y=5,xy=6,求x^2-xy^2和x^2y+xy^2
问题描述：
若x-y=5,xy=6,求x^2-xy^2和x^2y+xy^2
答
x = -1,y = -6或
x = 6,y = 1
代入式子得
x^2 - x y^2 = 37或30
x^2 y + x y^2 = -42或42