Question 131349: In a 6-mile run, Cindy finished 15 minutes ahead of Bill. Cindys speed was 2 miles per hour faster than Bills speed. What was Bills speed? Found 2 solutions by checkley71, josmiceli:Answer by checkley71(8403) (Show Source):
You can put this solution on YOUR website! 6/(x+2)+.25=6/x
[6+.25(x+2)]/(x+2)=6/x
[6+.25x+.5]/(x+2)=6/x
(6.5+.25x)/(x+2)=6/x
x(6.5+.25x)=6(x+2)
6.5x+.25x^2=6x+12
.25x^2+6.5x-6x-12=0
.25x+.5x-12=0
(.25x+2)(x-6)=0
x-6=0
x=6 mph is Bill's speed.
6+2=8 Cindy's speed.
proof
6/8+.25=6/6
.75+.25=1
1=1
You can put this solution on YOUR website! =distance in mi =rate in mi/hr =time in hours
write an equation for both of them This is Cindy's equation This is Bill's equation They ran the same distance, mi.
multiply both sides by
multiply both sides by
Solve by completing the square only the + root makes sense here mi/hr answer
check answer: hr mi/hr hr
OK
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