Question

Paul currently has $300 to spend on a data plan. He found a phone for $100 and a $50 a month charge.

Answer 1

Let x= months
So 50x is the total amount he pays after x months. You went to add 100 to this because there's a fixed cost of 100 for the phone
So you have the expression 100+50x which is the amount he pays after x months
Since he has a limit of 300,
100+50x < 300