John puts the letters of the word science on pieces of paper and puts the pieces in a bag. he draws two letters without looking. the first piece of paper is not replaced before the second piece is drawn. what is the probability that john draws a c twice?

Solve 3x-18=2y and 5x-6y=6 by elimination show work

Which property was used to simplify the expression? 3c+9 +4c=3c+4c+9

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?