4x - 5y - z= 18
-2x - 5y -2z= 12
-2x + 5y + z = 4

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