Question

5x的4次方乘以y+（m-2）乘以x的3次方乘以y的平方-(n+2)乘以x的平方乘以y的立方+5x乘以y的4次方中不含x

Answer 1

5x^4y+（m-2）x^3y^2-(n+2)x^2y^3+5xy^4中不含x^2y^3与x^3y^2的项,则m与n的值为?

由题意：不含x^2y^3与x^3y^2的项,则x^2y^3项与x^3y^2项的系数为0.

由题意：+（m-2）x^3y^2,所以x^2y^3项的系数是m-2.

由题意：-(n+2)x^2y^3,所以x^3y^2项的系数是-(n+2).

即：

m-2=0,m=2.

-(n+2)=0,n=-2.