Graph the two functions: y = 3x^2 and y = 3(2)^x. Do they both grow at the same rate? If not, explain which one grows faster and why it grows faster as compared to the other.

The interest rate is "simple", so he will pay 7% extra of what he borrowed back per year.
7% of $18,500 is $1,295
So over 3.5 years, he'll need to pay $1,295 x 3.5 which is $4,532.50 interest.
But remember he also owes the original amount he borrowed, so he'll owe $18,500 + $4,532.50 which is $23,032.50 total
Hope this helped