Which pair of complex numbers has a real-number product? O (1 + 2i(8i)
0 (1 + 2i) (2 - 5i)
O (1 + 2i)(1 – 2i)
O (1 + 2i)(4i)
h

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?

Of jk j(–25, 10) k(5, –20). is y- of l, jk a 7: 3 ? a. –16 b.–11 c. –4 d.–1

The angle of elevation from point a to the top of a cliff is 38 degrees . if point a is 80 feet from the base of the cliff , how high is the cliff ?