A substance has a half-life of 6 years. If 20 pounds are present initially, how much will remain after 2 years?

John can eat 10 cookies in 1/2 hr how many cookies can he eat in 45 minutes make a proportion and solve

Aline passes through the point (–7, 5) and has a slope of 1/2 which is another point that the line passes through?

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?