Jason charges $18 plus $4 per hour to mow lawns. Andrew charges $7 per hour with a $12 dollar up front cost. In what situation does Jason charge more than Andrew.
If it takes more than 2 hours to mow the yard. 18 +4x = 12+7x solves to 2, meaning they would cost the same at 2 hours of mowing. So anything larger than 2 hours means Andrew gets $3 more an hour than Jason
