X+ y = 4 2x + 3y = 0 a. x = -6, y = 2 b. x = -1, y = 5 c. x = 11 5 , y = 9 5 d. x = 12, y = -8

Use sigma notation to represent the following series for 9 terms.

What is the distance from zero if a quadratic function has a line of symmetry at x=-3 and a zero at 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?