The stopping distance d of a car after the brakes are applied varies directly as the square of the speed r. If a car travelling 60 mph can stop in 200 ft, how many feet will it take the same car to stop when it is travelling 50 mph?

It will approximately take 138.89 feet for the car to stop when travelling at 50 mph.

Step-by-step explanation:

We are given the following in the question:

"The stopping distance d of a car after the brakes are applied varies directly as the square of the speed r"

Thus, we can write:

Removing sign of proportionality and adding constant of proportionality, we get,

When d = 200, r = 60

Putting values, we get,

Thus, we can write the relation:

We have to evaluate the stopping distance, d when speed is 50 mph.

Putting r = 50 in the equation, we get,

Thus, it will approximately take 138.89 feet for the car to stop when travelling at 50 mph.

the answer is y < -3 or   y > 3

-3y > 7 + 2

-3 y > 9

y < -3