the formula for the cost is
c = l + p
Total cost is £47
Step-by-step explanation:
Let c represent the cost in £ of a monthly phone contract made up of the fixed line rental l in £ and the price p in £ of the calls made.
The formula for the cost, c would be
c = l + p
if the line rental is £35 and the price of calls made is £12, then, the total cost, c would be
c = 35 + 12 = £47