Monday

March 30, 2015

March 30, 2015

Posted by **jim** on Monday, August 16, 2010 at 10:18pm.

- algebra -
**drwls**, Monday, August 16, 2010 at 10:31pmCall the initial speed V (in miles/h) and the time driving at that speed be t (in hours).

V*t + (V+15)*(1-t) = 50

V*t = 30

30 + (V+15)(1 - 30/V) = 50

(V+15)(1 - 30/V) = 20

V + 15 -30 -450/V = 20

V - 450/V = 35

V^2 -35V -450 = 0

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

Only the positive root, V = 45 mph, makes sense. Rachel finishes the trip at 60 mph

**Answer this Question**

**Related Questions**

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

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

math....please help! - rachel allows herself 1 hour to reach a sales appt 50 ...

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

maths - A motorist travels 120 miles to his destionation at an average speed of ...

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

Calculus/ Optimization - A truck driver, on assignment from the owner of the ...

Math/ Calculus Please HELP!!! - A truck driver, on assignment from the owner of ...

college algebra - a bus driver wants to average at least 40 miles per hour on a ...

math - substitute to find the value of the expression. A train must cover a ...