The time required to drive a fixed distance varies inversely as the speed. it takes 40 hr at a speed of 10 km/h to drive a fixed distance. how long will it take to drive the same distance at a speed of 400 km/h?

Answer

1 hour.

Explanation

The first step is to find the constant of proportionality.

t ∝ s              Where t ⇒ time

                                 s ⇒ speed

t = k/s                     Where k ⇒ constant of proportionality.

40 = k/10

k = 40 × 10

    = 400

The formula now becomes;

t = 400/s

For 400 km/h time will be;

t = 400/400

 = 1 hour.

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.

a and c

step-by-step explanation: