What is 13 plus something equals 31?

Answer 1

Oh, dude, you're hitting me with the math questions? Okay, so if you want to know what number added to 13 equals 31, it's 18. I mean, you could've just asked me for the answer straight up, but hey, I'm here to help with your math mysteries.

Answer 2

The value that needs to be added to 13 in order to equal 31 can be found by subtracting 13 from 31, which equals 18. Therefore, the answer is 18.

Answer 3

13 + X = 31

Or

31 - 13 = X

Ergo X = 18

Answer 4

23