A car has 21 gallons of gasoline in its tank when it starts its journey. On a long highway
trip, gasoline is used at a rate of about 3.5
gallons per hour. The gallons of g remaining
in the car's tank after 7 hours can be modeled
by the function g(t) = 21 - 3.5t
What does g(4) = 7 represent?

If there are 12 moths and some have 31 days and others have 30 days how many have 28 days?

True or false: the graph of y=f(bx) is a horizontal compression of the graph y=f(x) if b< 1

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?