The percent of discount is 55% and the sale price is $90. What is the original price

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?

Yvaries directly as x. y =90 when x=6. find y when x=13

Need plz been trying to do it for a long time and still haven’t succeeded