Friday

July 25, 2014

July 25, 2014

Posted by **john** on Tuesday, February 17, 2009 at 11:16pm.

- math....please help! -
**Reiny**, Tuesday, February 17, 2009 at 11:35pmIf you had worked out my solution from several pages back

http://www.jiskha.com/display.cgi?id=1234871808

you would have realized that it was a simple typo, but my factors and my solution was correct.

I will repeat the corrected version

**let her speed for the first leg be x mph**

let her speed for the second leg be x+15 mph

so her time for the first leg is 30/x

her time for the second leg is 20/(x+15)

but 30/x + 20/(x+15) = 1

multiplying both sides by x(x+15) and simplifying I got

x^2 + 35x - 450 = 0

(x+10)(x-45) = 0

x = -10, which is silly or

x = 45 mph

check:

30/45 + 20/60 = 1

- math....please help! -
**Reiny**, Tuesday, February 17, 2009 at 11:36pmoops, copied it and forgot to change the typo, silly me.

let her speed for the first leg be x mph

let her speed for the second leg be x+15 mph

so her time for the first leg is 30/x

her time for the second leg is 20/(x+15)

but 30/x + 20/(x+15) = 1

multiplying both sides by x(x+15) and simplifying I got

x^2 - 35x - 450 = 0

(x+10)(x-45) = 0

x = -10, which is silly or

x = 45 mph

- math....please help! -
**john**, Tuesday, February 17, 2009 at 11:41pmthank you so much, I really appreciate your time.

**Related Questions**

college algebra word problem - rachel allows herself 1 hour to reach a sales ...

algebra - rachel allows herself one hour to reach a sales appointment 50 miles ...

algebra - Rachel allows herself 1 hour to reach a sale appointment 50 mile s ...

algebra word problem: still stuck - question: rachel allows herself 1 hour to ...

Math - A small truck is to be driven 300 miles on a freeway at a constant speed ...

math - 1. Which situation is not a function? a) the number of days d below ...

MATH - From HOME TO THE FAIR IT'S 70 MILES, I have driven about 30 miles at 40 ...

math - From a point on a straight road, two cars are driven in opposite ...

Math - At the last school pep rally 4 out of every 6 students wore school colors...

Science - If a truck that has a back ramp on it is going 70 miles an hour down ...