SOMEONE HELP
PLS EXPLAIN STEP BY STEP WHAT TO DO IM SO CONFUSED

The sum of the speeds of two trains is 720.2 mph. if the speed of the first train is 7.8 mph faster than the second train, find the speeds of each.

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?

Sasha delivers newspapers to subscribers that live within a 4 block radius of her house. sasha's house is located at point (0, -1). points a, b, c, d, and e represent the houses of some of the subscribers to the newspaper. to which houses does sasha deliver newspapers?