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
3/8 + x
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3 5/12
2 answers
-15=5+2t
__ __
3 5/12
2 answers