SOLUTION: Two cars start from two towns 400 miles apart and travel towards each other. They pass each other after 4 hours. Find the speed of each car if their difference between their speeds

Algebra ->  Test -> SOLUTION: Two cars start from two towns 400 miles apart and travel towards each other. They pass each other after 4 hours. Find the speed of each car if their difference between their speeds      Log On


   

Question 353943: Two cars start from two towns 400 miles apart and travel towards each other. They pass each other after 4 hours. Find the speed of each car if their difference between their speeds is 30 miles per hour.
Found 3 solutions by rfer, slitco, Alan3354:
Answer by rfer(16322) About Me  (Show Source):
You can put this solution on YOUR website!
400/(2x+30)=4
400=8x+120
8x=280
x=35 mph
x+30=65 mph

Answer by slitco(2) About Me  (Show Source):
You can put this solution on YOUR website!
x = slower car
x + 30 = faster car
-------------------
(x+30)(4) + (x)(4) = 400
4x + 120 + 4x = 400
8x + 120 = 400
8x = 280
x = 35
------------------
35 mph (slower car)
35 + 30 = 65 mph (faster car)


Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Two cars start from two towns 400 miles apart and travel towards each other. They pass each other after 4 hours. Find the speed of each car if their difference between their speeds is 30 miles per hour.
------------
They meet in 4 hours, so the sum of their speeds is 100 mi/hr
F + S = 100
F - S = 30
---------------------- Add
2F = 130
etc