3x - 4y = 7 ; Solve for x
We're essentially just trying to get "x" onto it's own side.
So, in order to do this, we must get "y" onto the other side of our equal sign.
Add 4y to both sides.
3x = 4y + 7
Then, we divide 3 from both sides.
x = 4/3y + 7/3
15y + 1 = x ; Solve for y.
Instead of solving for x, we are now solving for y :)
So, in order to isolate y, we must subtract 1 from both sides.
15y = x - 1
Then, divide both sides by 15.
y = 1/15x - 1/15
~Hope I helped!~