The Miller's are comparing babysitting services for their two children.
The Babysitter's Block charges a rate of $15 an hour per child plus an initial fee of $25 per household.
Super Sitters charges a flat rate of $20 an hour per child.
Let the number of hours when they will be equal =H
25 + 15H =20H
20H - 15H =25
5H =25 divide both sides by 5
H = 5 hours-when they will be equal.