An electrician charges $45 for each home visit plus $19.95 every hour he spends working. Which sentence could be used to find C, the cost in dollars for a house visit and h, hours of work ? F. C = 45 + 19.95h G. C = 45h + 19.95 H. C = (45 + 19.95)h J. C = (45 - 19.95)h

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?