How do you solve 12 over y equals 5?

12 .... 5

---- = ---

y ......1

So 12(1) = 5(y) (because product of "means" and "extremes" are equal)

Just remember that when you have two equal fractions, the cross-products must be equal. There are other ways, but this way will often get you to where you want to go faster.

y = 12/5

12/y=5. Multiply each side by y. That gives you 5y=12. Divide each side by 5. That gives you y=12/5, or 2.4.