Use the formula A=P(1+r)^t to find the rate r at which $3000 compounded annually grows to $6750 in 2 years

use the formula A=P(1+r)^t to solve the following problem find the rate at which $100,000 grows to $129,960 in 2 years

I'm trying to help a friend, but I didn't learn this when I did algebra a couple years ago

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?