Evaluate 7r -\dfrac{15}s7r− s 15 7, r, minus, start fraction, 15, divided by, s, end fraction when r=3r=3r, equals, 3 and s=5s=5s, equals, 5.

Adan has decided to purchase an $9000 car. he plans on putting 20% down toward the purchase and financing the rest at 7.9% interest rate for 3 years. find his monthly payment a) $225.29 b) $298.81 c) $204.78 d) $236.89