8x over 8 to the power of 5 = 8 to the power of 7

On saturday morning, calls arrive at ticketmaster at a rate of 108 calls per hour. what is the probability of fewer than three calls in a randomly chosen minute?

Joseph haydn pet store offers wide variety of leashes for dogs. the store purchases one popular type of leash from its manufacturer for $4.38 each. joseph haydn pets marks up leashes at a rate of 238% of cost. what is the retail price of the popular leash?

What is the value of x when x + 7 = 21?