1 subscription = $21 28 subscriptions = x You know 1 subscription is $21 You want to find out how much 28 subscriptions are Multiply 28 (subscriptions) by 21 ($ per subscription) 28 x 21 = 588 28 subscriptions cost $588 If you would like the formula to find out how many subscriptions cost hat amount of money, 21x = y x is how many subscriptions you want, while y is the total cost of the money