Ara buys two items that cost d dollars each. she gives the cashier $20. which expression represents the change she should receive? question 8 options: a 20 - 2d b 20 - d c 20 + 2d d 2d - 20

One card is dealt from a 52 card deck. find the probability that the dealt card is a 4 or a black 7

Find the amplitude of a sinusoidal function that models this temperature variation

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?