c-5/4=3

Please explain. I don't get it!

As I explained earlier, you need to get the unknowns on one side and the knowns on the other side.

c-5/4=3

Add 5/4 to both sides of the equation.

c -5/4 + 5/4 = 3 + 5/4

c = 3 5/4 = 4 1/4

Let's check it by substituting 4 1/4 for c.

4 1/4 - 1 1/4 = 3
Right!