Explain? thank you <3 GEOMETRY

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?

Find an equation of the line perpendicular to the graph of 28x-7y=9 that passes through the point at (4,1)

Look at this pattern ; 1,4,9, number 10000 belongs in this pattern . what’s the place of this number?