Answer:
r = 4
Step-by-step explanation:
3r = 12, the goal is to get the expotent by itself. To do this, you have to divide 3 from r, but then you must do it to the other side. 3r/3 will eliminate the 3, leaving you with r = 12/4, which 12/4 is 3. Leaving you with r = 4
