Which of the following coordinates is a point on the graph g(x), if 12 = g(-3)?

Marlow is comparing the prices of two trucks rental compaines company a charges $3 per hour and an addtional $75 as serivce charges company b charges $2 per hour and an additional $85 as serivce charges

Can any one me with the answers to these questions asap?

Last month, a 770 g box of cereal was sold at a grocery store for $3.10. however, this month, the cereal manufacturer launched the same cereal in a 640 g box, which is being sold at $2.50. what is the percent change in the unit price?