Question

1.写出一个含两个字母,系数是2,次数是4的单项式?

Answer 1

1.2x^2y^2

2.2-3a+6b=2-3(a-2b)=2-3=-1

3.n=2,m=3,m+n=5

4.5a^3b,3ab^3--2ab,-2b^2