What is the coefficient of $xy$ in the expansion of $(3x+(2y+1))^2$?

  $$$(3x+(2y+1))^2$$

This term would be

C(2,1)*(3x)^1 *(2y + 1)^1  =

2(3x)(2y + 1) =

6x(2y + 1) =

12xy + 6x

So....the coefficient is 12

Thanks Chris,

This can be easily done by any good yr 9 student.

$$\\\boxed{(a+b)^2=a^2+2ab+b^2}\\\\ so\\\\ (3x+(2y+1))^2\\ =(3x)^2+2*3x*(2y+1)+(2y+1)^2\\ =etc\\\\ $The only term with xy is going to be $ \\ 2*3x*2y=12xy\\ $so the coefficient of xy is 12$$ $