math
posted by Kay .
Use an inequality to solve the problem. Be sure to show the inequality and all of your work. A car rental company has two rental rates. Rate 1 is $63 per day plus $0.18 per mile. Rate 2 is $126 per day plus $0.09 per mile. If you plan to rent for one week, how many miles would you need to drive to pay less by taking Rate 2?

let the number of miles driven be x
when is .09x + 126 ≤ .18x + 63 ?
times 100
9x + 12600 ≤ 18x + 6300
9x ≤  6300
x ≥ 700 
x >700