Description: If you're coming to this video before seeing the previous one, back up! Otherwise, we're solving one-step equations to learn which Super Plan is the best value for our budget. Created by Sal Khan. Now that we've set up our equations, let's see if we can answer some more interesting questions. So as a starting point, let's think about how much, under the basic plan, it'll cost for us to attend 3 sessions in a given month. Our total cost in that month is going to be equal to 20 plus 8 times the number of sessions.*Teacher Advisor is 100% free.