See attached file for full problem description.
1. After an accident, how do police determine the speed at which the car had been traveling?
The formula r = 2 sqrt(5L) can be used to approximate the speed r, in miles per hour, of a car that has left a skid mark of length L, in feet.
How far will a car skid at 65mph? at 100 mph?
2. simplify the radical expression
It shows detailed steps of calculation of the speed of the car from the length of skid mark by solving a radical equation.