1. You design a new app for cell phones. Your revenue for x downloads is given by f(x) = 2x. Your
profit is $30 less than 80% of the revenue for x
downloads. Create a function p to model the profit.
Find the profit for 120 downloads.

Ineed if you could explain and give me the answer you! this needs done

Solve this system of equations. 12x − 18y = 27 4x − 6y = 10

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?