Derrick's Doggie Day Care charges a $12 registration fee plus $5 per hour for pet sitting. Pauline's Pooch Park charges $3 per hour plus an $18 registration fee. Which inequality can be used to find the number of hours, h, for which the cost of Derrick's Doggie Day Care is at most the cost of Pauline's Pooch Park?

Aspacecraft can attain a stable orbit 300 kilometers above earth if it reaches a velocity of 7.7 kilometers per second. the formula for a rocket's maximum velocity v in kilometers per second is vequalsminus0.0098tplusc ln upper r, where t is the firing time in seconds, c is the velocity of the exhaust in kilometers per second, and r is the ratio of the mass of the rocket filled with fuel to the mass of the rocket without fuel. find the velocity of a spacecraft whose booster rocket has a mass ratio of 20, an exhaust velocity of 2.1 km/s, and a firing time of 15 s. can the spacecraft achieve a stable orbit 300 km above earth?