Question :

If,

6 + 4 = 210

9 + 2 = 711

8 + 5 = 313

5 + 2 = 37

7 + 6 = 113

9 + 8 = 117

10 + 6 = 416

Then,

15 + 3 = ???

Answer : Please provide the answer in comments below.

The number series is as shown below:

6+4 = (6-4)(6+4)=210,

9+2=(9-2)(9+2)=711

8+5=(8-5)(8+5)=313

So,

15+3=(15-3)(15+3)=1218

So answer is 1218.