Question

3/8 + x

__ __
3 5/12

Answer 1

If you want to solve for x, I assume your problem can be written this way:

3/8 + x / 3 5/12
3/8 - 3/8 + x = 3 5/12 - 3/8
x = 3 10/24 - 9/24
x = 3 1/24

Answer 2

-15=5+2t