Answer:

Step-by-step explanation:
So we have the expression:

Distribute. Multiply (4x+5) to each term:

Distribute:

Combine like terms:

Add and simplify:

And this is in descending order, so it's in standard form.
The answer would probably be the last one cuz it’s true and it has more then one thing
8 am at 0
8:18 at 4.5
8:48 at 7.5 miles ???
18 min = .3 hour
48 min = .8 hour
in first .3 hours speed = 4.5/.3 = 15 mph
in next .5 hours = speed = 3/.5 = 6 mph
average speed for the whole trip = 7.5 miles/.8 hours = 9.375 mph
X - y = 2400/6 = 400 where x = speed of plane and y = speed of wind.
x + y = 2400/5 = 480 - flying with the wind
adding the 2 equations
2x = 880
x = 440
Speed of the plane with no wind = 440 mph
So floor that you started is x
go down 8 means -8
end on 16
so
x-8=16
add 8
x=24
started on 24