A-6=b. if a =45 so what is the answer

I’m confused on how to work the pie charts

In a rectangle klmn, km = 6x + 16 and ln = 49. find the value of x

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