After traveling for 4 hours and 1800 miles, an airplane begins a steady descent. when it begins descending, it’s altitude is 33,000 ft. after 8 minutes it is at 17,000 ft. how quickly did the airplane descend?

the speed of descend is 2,000ft/min

and the time to totally descend is 16.5 minutes

Step-by-step explanation:

To know how quickly the airplane descended, we need to find the speed of descend.

We use the formula for speed:  

we find the distance by substracting the final altitude from the initial altitude:

initial altitude: 33,000ft

final altitude: 17,000 ft

so the distance is:

33,000 - 17,000 = 16,000 ft

and the time is:

time = 8 minutes

and we substitute the distance and time into the speed equation:

this is how quicky the airplane descended in feet per minute.

If what you need to know is how much time is took to get to the ground then from the equation for speed we clear for the time:

and to totally descend the distance that the airplane has to travel is 33,000 ft, so:

it takes 16.5 minutes to descend to the ground

x= -3 and

step-by-step explanation:

to find the roots of a cubic, use division or factoring to find the factors then set equal to 0. as this is a difference of cubes, it factors into

where a is the cube root of .

here   this is 27 and the cube root of 27 is 3. so we write using the form:

.

set each factor to 0 and solve for x.

x-3=0

x=3

the quadratic expression does not factor and must be solved using the quadratic formula.

where a = 1, b=3, and c=9

this cubic has two complex roots.

make sure you have version 2.50

try looking in the very back of the book : )

step-by-step explanation:

you can download it here