Question 37717
First...
One number (n) is 12 more than another (n+12).
The sum of the smaller number (n)
and twice the larger number  + 2(n+12)
is 39 (=39)
So lets put that formula together.
n + 2(n + 12) = 39
Distribute...
n + 2n + 24 = 39
Subtract 24 from each side...
n + 2n = 15
Add like terms...
3n = 15
Divide both sides by 3...
n = 5
So, the smaller number (n) = 5
The larger number (n + 12) = 17
The correct answer is... a. 17