You get a raise on your allowance of $5/month, as long as you maintain good grades. after 7 months you have an allowance of $65. write an equation in point slope form for the situation:

The equation would be y=5x+30   x= the months. You multiply 7*5 to see how much things increased, which was by 35. This means that to equal 65 you had to start with 30, so 30 becomes the base price.

Are you trying to figure out the volume?