The answer is a+6b, if you want to know the proof please comment on this post
FOIL (distriute)
tells how to multiply which ones
First terms
Inner terms
Outer terms
Last terms
(2n+2)(6n+1)
First (2n times 6n=12n^2)
Inner (2 times 6n=12n)
Outer (2n times 1=2n)
Last (2 times 1=2)
add them
12n^2+12n+2n+2
12n^2+14n+2