The equation y=5.5x represents a proportional relationship. what is the constant of the proportionality?

Find the condition that the zeros of the polynomial f(x) = x^3+3px^2+3px+r may be in a.p.

Gabrielle's age is two times mikhail's age. the sum of their ages is 84. what is mikhail's age?

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?