5(x+y)²-3(x+y)³+(y+x)²-8(y+x)³ 怎么样求解这样的多项式?

5(x+y)²-3(x+y)³+(y+x)²-8(y+x)³ 怎么样求解这样的多项式?
5(x+y)²-3(x+y)³+(y+x)²-8(y+x)³ 怎么样求解这样的多项式?

5(x+y)²-3(x+y)³+(y+x)²-8(y+x)³ 怎么样求解这样的多项式?
5(x+y)²-3(x+y)³+(y+x)²-8(y+x)³
=5(x+y)²-3(x+y)³+(x+y)²-8(x+y)³
=6(x+y)²-11(x+y)³