Choose all the equations that are true if x=8. 7/9 x = 6 2/9
7/9 x = 6 2/9

x + 11.5 = 20.5
x + 11.5 = 20.5

23.42 - x = 15.42
23.42 - x = 15.42

11x = 88
11x = 88

40 Divided by x = 6
40 Divided by x = 6

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?