What is the product of 3/4 and -6/7?

-7/8

-9/14

9/14

7/8

Ineed in figuring out this problem.

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?

Suppose that the function f is defined. , for all real numbers, as follows. _ \ 1/4x² -4 if x≠ -2 f(x)=< /_-1 if x=-2 find f(-5), f(-2), and f(4)