The phone company A Fee and Fee has a monthly cellular plan where a customer pays a flat monthly fee and then a certain amount of money per minute used on the phone. If a customer uses 210 minutes, the monthly cost will be $87. If the customer uses 990 minutes, the monthly cost will be $321. A) Find an equation in the form y = m x + b , where x is the number of monthly minutes used and y is the total monthly of the A Fee and Fee plan. y = ___ Do not use any commas in your answer. B) Use your equation to find the total monthly cost if 756 minutes are used. If 756 minutes are used, the total cost will be ___ dollars. fill in the blanks