Answer:
John can use no more than 2 GB of additional data
Step-by-step explanation:
Monthly fee = $40
Additional fee = $15 for each 1 GB of data (rounded up) over his 8 GB.
Let x be the number of additional data in GB over his 8 GB of data that comes with his plan.
Total monthly charge is
It is given that monthly charge before taxes to be at most $70.
Divide both sides by 2.
Therefore, John can use no more than 2 GB of additional data.