Question

An equipment rental company charges a flat rate of $25, plus $13 per day for insurance. Kyle has $121. Write an inequality to represent the number of days, d, for which he can rent equipment

Answer 1

The inequality begins with the flat fee of $25.  We then add the $13 per day for insurance as 13d, where d is the number of days.  This gives us the expression
25 + 13d.  Since he only has $121, we must use less than or equal to for our inequality; he can't spend any more than $121, but he can spend any number below it up to that number.  This gives us
25 + 13d ≤ 121