You have $55 and are buying some DVD's that cost $12 each. Write an expression for how much money you have left after buying n discs.

Question

Evaluate the expression when n=3 and n=4

Answer 1

Every time you buy a DVD you subtract $12 from your starting $55. So if you buy n DVDs, you subtract $12n. So the expression is:

$55 - $12n

To evaluate at n = 3, plug 3 in for n in the expression. Repeat for n = 4.