若m=x^3-3x^2y+2xy^2+3y^3,n=x^3-2x^2y+xy^2-5y^3,则2x^3-7x^y+5xy^2+14y^3的值是

分类: 作业答案 • 2023-01-04 00:08:51

问题描述：

若m=x^3-3x^2y+2xy^2+3y^3,n=x^3-2x^2y+xy^2-5y^3,则2x^3-7x^y+5xy^2+14y^3的值是
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答

2x^3-7x^y+5xy^2+14y^3=3(x^3-3x^2y+2xy^2+3y^3)-(x^3-2x^2y+xy^2-5y^3)
=3m-n