What are the three characteristics of a good math explanation?

Can someone answer it, and plot it, for 20 points and brainliest answer? p. s. they're the same ! : )

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?

Drag the tiles to the correct boxes to complete the pairs. match the cart-coordinates with their corresponding pairs of y-coordinates of the unit circle