Grace was given the description “three less than the quotient of a number squared and nine, increased by eight” and was asked to evaluate it when n = 6. Her work is shown below. Step 1: 3 minus StartFraction n squared Over 9 EndFraction + 8 Step 2: 3 minus StartFraction 6 squared Over 9 EndFraction + 8 Step 3: 3 minus StartFraction 36 Over 9 EndFraction + 8 Step 4: 3 minus 4 + 8 Step 5: 7 In which step did she make an error? step 1 step 2 step 4 step 5

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?