<PRE><B>Question 181931</B>
The formula for calculating the braking distance needed when traveling at a certain speed is d=x^2/20 + x, where x is the speed of the car and d is the stopping distance. Calculate the stopping distance required when a car traveling 20 mph, 40 mph, 60 mph, and 60 mph. 
:
:

d = {{{x^2/20}}} + x
:
20 mph:
d = {{{20^2/20}}} + 20
d = {{{400/20}}} + 20
d = 20 + 20
d = 40&#39;
:
60 mph
d = {{{60^2/20}}} + 60
d = {{{3600/20}}} + 60
d = 180 + 60
d = 240&#39;
:
you should be able to do it for 40 mph and 80 mph the same way</PRE>