How to find y in the equation: 5x + 4y =7

Question

I'm trying to learn some algebra formulas and apply them to equations like this one.

Answer 1

5x + 4y = 7                 Given

5x + 4y - 5x = 7 - 5x    Subtract 5x from each side

4y = 7 - 5x                  Simplify

4y/4 = (7 - 5x)/4         Divide each side by 4

4y/4 = 7/4 - (5/4)x      Distribute the /4 on the right side

y = 7/4 - (5/4)x           Simplify the left side