Write a situation about today's sales for the following systems of equations and then determine how much of each menu item you sold e f = 48 and e = 3f

If y varies directly as x2 and y=6 when x=6, find the constant of variation.

Complete the solution of the equation. find the value of y when x equals to 6 4x+y=20

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?