SOLUTION: Two people start driving toward each other on the same highway at the same time from towns 420 miles apart. one car travels 15 mph faster then the other. what is the rate of each c

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Two people start driving toward each other on the same highway at the same time from towns 420 miles apart. one car travels 15 mph faster then the other. what is the rate of each c      Log On


   



Question 188474: Two people start driving toward each other on the same highway at the same time from towns 420 miles apart. one car travels 15 mph faster then the other. what is the rate of each car if they meet in 4 hours?

answer: the first car travels 60 mph; the second car travels at 45 mph.

need a full break down of how my book got this answer i know that i have to use r=d/t

Answer by Mathtut(3670) About Me  (Show Source):
You can put this solution on YOUR website!
d=r*t
:
d=(r+15)4...eq 1---->d=4r+60.......fast car
420-d=r(4)..eq 2---->d=-4r+420.....slow car
:
4r+60=-4r+420
:
8r=360
:
r=45 slow car
:
r+15=60...fast car
: