Which polynomial represents the sum below? 3x^6 +4x+3 3x^8+6x + a. 3x8 + x6 + 4x + 3 b. 6x14 + 4x + 3 c. 3x8 + 3x6 + 10x + 3 d. 3x8 + 10x7 + 13x + 4

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?