Please help I will give 10 points​

Given the graphed function below which of the following orders pairs are found on the inverse function

I'm at a bookstore with $\$35$ in my pocket and a $20\%$-off coupon. what is the cost of the most expensive book i can buy with my money and the coupon? (assume that there are books of every possible price in the bookstore. it's a large bookstore! )

Solve the equation: x - 9 = -6 + 5 a. 21 b. 7 c. 14 d. 2