When I have the problem (x−2)^2, why is the answer not x^2−4 or x^2+4?

Someone me! if you’re smart you can solve this!

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?

Shelly bought a house five years ago for $150,000 and obtained an 80% loan. now the home is worth $140,000 and her loan balance has been reduced by $12,000. what is shelly's current equity?