Explanation:
write what you know
the flat fee doesnt chamge no matter how much he uses his data
the charge for every gigabyte does change
Ex: if he uses 3 gigabytes of data in one month, that's
5 + 5 + 5 = $5 x 3 = $15
So taking this into consideration youd write the following
$41.50 + $5x = $52.50 (since this is what we want to equal)
then solve for x