y = mx + b
1.) -6x + y = 4
Move variable x over to the other side by adding 6x.
y = 6x + 4
2.) -y - 2x = 4
Move variable x over to the other side by adding 2x.
-y = 2x + 4
Divide the whole thing by -1 because y needs to be positive and alone.
y = -2x - 4
