Question

已知关于xy的多项式6mx平方+4nxy+2x+2xy-x平方+y+4不含二项式，求6m-2n+2的值！！

速求 答案 一定要有 步骤 ， 看得清楚 ！！ 谢谢

Answer 1

6mx²+4nxy+2x+2xy-x²+y+4
=(6m-1)x²+(4n+2)xy+2x+y+4
前两项是二次项
所以他们的系数是0
6m-1=0.4n+2=0
6m=1,2n=-1
6m-2n+2=1+1+2=4

Answer 2

已知关于xy的多项式6mx平方+4nxy+2x+2xy-x平方+y+4不含二次项，求6m-2n+2的值
6mx平方+4nxy+2x+2xy-x平方+y+4
=(6m-1)x²+(4n+2)xy+2x+y+4
6m-1=0
4n+2=0
m=1/6
n-1/2

6m-2n+2
=6*1/6-2*(-1/2)+2
=1+1+2
=4

Answer 3

6mx²+4nxy+2x+2xy-x²+y+4
=(6m-1)x²+(4n+2)xy+2x
6m-1=0.4n+2=0
6m=1,2n=-1
6m-2n+2=1+1+2=4