If 8+6 = 12, 9+9 = 9 then 8+7=??

Question

If
2,6=5
4,9=7
6,11=8
8,15=11
then
12,18=?

Answer 1

8+6 =12
Which means 8×6=48 and 4+8=12

9+9 = 9
Means 9×9 = 81 and 8+1 = 9

So
8+7 = 11

Which means 8 × 7 = 56 and 5 + 6 = 11

In General,

a + b = sum of the product of a × b

Answer 2

If 8+6 = 12, 9+9 = 9 then 8+7=??
Is it
8+6=12 : 3/2(4( the number of factor in number 8) + 4(the number of facters in number 6))= 3/2 x 8= 12
9+9=9 : 3/2(3(1,3,9 so 3 factors.) + 3( 1,3,9 so 3 factors ))= 3/2 x 6= 9

so 8+7= 9

is this corect? please let me know

Answer 3

If 8 + 6 = 12 8 * 6 = 48 and 4 + 8 = 12
If 9 + 9 = 9 9 * 9 = 81 and 8 + 1= 9
Then,
8 + 7 = ? 8 * 7 = 56 and 5 + 6 = 11

The answer is 11