The answer to your problem is 4.32.
3x5=$15
15+10=$25 total to spend
He spends 12.75+8.5= $21.25
25-21.25=$3.75 left
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
The answer is 43 because it is half of 86 which is the radius
