Lisa and julia are selling cookie dough for a school fundraiser. customers can buy packages of sugar cookie dough and packages of chocolate chip cookie dough. lisa sold 13 packages of sugar cookie dough and 6 packages of chocolate chip cookie dough for a total of $252. julia sold 8 packages of sugar cookie dough and 12 packages of chocolate chip cookie dough for a total of $288. find the cost of each of one package of sugar cookie dough and one package of chocolate chip cookie dough.
x = y =
equations:
1.
2.
solution:

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?