Answer:
Linear equation for the monthly cost of the cell plan is

Explanation:
Let u denotes a flat monthly fee and v denotes amount charged per minute.
As the monthly cost is $71.50 if a customer uses 410 minutes,
(i)
As the monthly cost is $118 if a customer uses 720 minutes,
(ii)
Subtract (i) from (ii)

Put
in (i)

As x denotes the number of monthly minutes used,
linear equation for the monthly cost of the cell plan is
