If f(x) varies directly with x and f(x) = 32 when x = -8, then what is f(x) when x = 4?

Ateacher has $80 to buy workbooks. each work book cost $3. if she buys as many workbooks as possible, how much money does she have leftover? a) $2 b) $4 c) $6 d) $8

Need on this one asap im almost done with this subject

Moira has a canvas that is 8 inches by 10 inches. she wants to paint a line diagonally from the top left corner to the bottom right corner. approximately how long will the diagonal line be?