Which equation can be used to solve the matrix equation [1/2 -1/4 2 3/4] [x y] = [2 -4 1 6]

Find the sum of the measure of the interior angles of a polygon of 9 sides ; of 32 sides

Using the figure below, select the two pairs of alternate interior angles.a: point 1 and point 4 b : point 2 and point 3 c: point 6 and point 6d: point 5 and point 7

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?