Question

the formula r=2sqrt5L can be used to approximate the speed r, in mph, of a car that has left skid marks in length L, in feet. How far will a car skid at 60 mph?

Answer 1

replace r by 60

Answer 2

I did that

Answer 3

can't figure how to solve for L

Answer 4

\[60=2\sqrt{5L}\]
\[30=\sqrt{5L}\]
\[900=5L\]
\[L=180\]

Answer 5

steps were
1) divide by 2
2) square both sides
3) divide by 5

Answer 6

ok thanks! got it!

Answer 7

yw