Please answer this is due in two hours. Please help!

Malia is observing the velocity of a cyclist at different times. after two hours, the velocity of the cyclist is 15 km/h. after five hours, the velocity of the cyclist is 12 km/h. part a: write an equation in two variables in the standard form that can be used to describe the velocity of the cyclist at different times. show your work and define the variables used. (5 points) part b: how can you graph the equations obtained in part a for the first 12 hours? (5 points) if you can try and make this as little confusing as you can

Ill mark the brainliest if you me with the these three questions 7,8,9

Arestaurant offers delivery for their pizzas. the total cost the customer pays is the price of the pizzas, plus a delivery fee. one customer pays $23 to have 2 pizzas delivered. another customer pays $59 for 6 pizzas. how many pizzas are delivered to a customer who pays $86?