Mathew decides to run his first 50K (km) Ultra-Marathon. If 0.62 miles = 1 km, how many miles is Mathew going to run? * (please respond, and quick!!)

What is the value of n in the equation -1/2(2n+4)+6=-9+4(2n+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?

Layla answer 21 of the 25 questions on his history test correctly.what decimal represents the fraction of problem he answer incorrectly.