2x-3y=8 solve i don't understand this at all can someone ? ?

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! )

25 ! what is the value of x? enter your answer in the box. x =

Avideo game enthusiast saved $750 to spend on a video game player and games. the player costs $400. the games costs $49 each. at most how many games can this enthusiast buy along the player