In order to make 'q' the independent variable in the equation, you need to solve for 'r'. The dependent variable would be 'r' because it depends on the value of 'q' to be solved. We can solve for 'r' by using inverse operations and completing the same operation on both sides of the equation. Starting with the initial equation and solving for 'r':
-7q + 12r = 3q -4
Add '7q' to both sides: -7q + 7q + 12r = 3q - 4 + 7q or 12r = 10q - 4