Find the least common denominator for these two rational expressions,

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?

Jonathan puts $400 in a bank account. each year the account earns 6% simple interest. how much interest will be earned in 5 years?

If a sprinkler waters 1 over 12 of a lawn in 1 over 2 hour, how much time will it take to water the entire lawn? (5 points) 10 hours 6 hours 1 over 6 hour 7 over 12 hour