The amount of water in a bathtub as it drains can be modeled by this equation with y representing the number of gallons of water in the tub and x representing the time, in minutes, that the tub has been draining. y=−7.3x+39.7 after how many minutes will the tub have 17.8 gallons of water remaining? enter your answer in the box.

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?