5+2=7, so the first blank is 2.
For the second blank, you just need two numbers in the box that when added, equals 7. (So 1,6 or 3,4)
It isn't proportional because 3/4 is proportional to 9/16 not 9/15.
Answer: A
I used my graphic calculator
Divide -8 from both sides to get the answer
