Find -3a+6b matrices i don’t understand how to solve these with an equation (-3a+6b)

Which of these is and example of a literal equation? a) 6+30=6^2 b)3x-4y c)12=9+3x d)ax-by=k

At store a, erasers are sold individually. the cost y of x erasers is represented by the equation y=0.75x. the costs of erasers at store b are shown in the graph.

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