John's wants to open a bank account with $100. He will have to pay a service fee of $5 per month to keep it open. Let y represent the amount of money in his account and x represent the number of months.

y+5x

Step-by-step explanation:

Y is the start so you have to add that to the amount of money total for all of the months and to get the total of the months you have to multiply 5 by the number of months he had the account open

$9.89

step-by-step explanation:

9.90 = p x .06 x .25 (3/12 changed to a decimal)

9.90 = p x 0.015

9.90 - 0.015 = p

9.89 = p