Which equation requires the multiplication property of equality to be solved?

The circumference of a circle is 5 pi cm. what is the area of the circle?

Giuseppi's pizza had orders for $931.00 of pizzas. the prices were $21 for a large pizza, 514 for a medium pizza, and $7 for a small pizza. the number of large pizzas was two less than four times the number of medium pizzas. thenumber of small pizzas was three more than three times the number of medium pizzas. how many of each size of pizza were ordered?

Write an equation in point-slope form for the line through the given point that has the given slope (-2,-7); m=-3/2