Consider the following graph of y = f (x). Please help

Solve the system of equations. y= 2x y= x^2 - 15

If x varies directly as y, and x = 7.5 when y = 10, find x when y = 4

Jackson earns $25 per hour as a tutor at the college library. he set a weekly spending budget of $130 each week and puts the remaining money in his savings account. how many hours must he work this week to have at least an extra $50 to put in his savings account