An airplane travels 4688 kilometers against the wind in 8 hours and 5808 kilometers with the wind in the same amount of time. what is the rate of the plane in still air and what is the rate of wind

The speed of wind is 656 kmph and speed of plane is 70 kmph.

SOLUTION:

Given that, an air-plane travels 4688 kilometers against the wind in 8 hours

And 5808 kilometers with the wind in the same amount of time.  

We have to find the rate of the plane in still air and the rate of wind

Now, let the speed of wind be a kmph and speed of plane be b kmph.

And we know that,

Substituting (1) in (2) we get,

On substituting (3) in (1) we get,

Hence, the speed of wind is 656 kmph and speed of plane is 70 kmph.

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15