SOLUTION: A car left the house traveling north at 10 A.M. Another car left the house traveling south two hours later. If the cars traveled at the same rate and were 550 miles apart at 4 p.m.

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: A car left the house traveling north at 10 A.M. Another car left the house traveling south two hours later. If the cars traveled at the same rate and were 550 miles apart at 4 p.m.      Log On


   



Question 305266: A car left the house traveling north at 10 A.M. Another car left the house traveling south two hours later. If the cars traveled at the same rate and were 550 miles apart at 4 p.m., what was the rate of each car?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Write a separate equation or each car
Car traveling north:
d%5B1%5D+=+r%5B1%5D%2At%5B1%5D
Car traveling south:
d%5B2%5D+=+r%5B2%5D%2At%5B2%5D
given:
d%5B1%5D+%2B+d%5B2%5D+=+550 mi
r%5B1%5D+=+r%5B2%5D (call it r)
Car 1 traveled north for 6 hrs
Car 2 traveled south for 4 hrs
------------------------------------
d%5B1%5D+=+r%2A6
d%5B2%5D+=+r%2A4
d%5B2%5D+=+550+-+d%5B1%5D
550+-+d%5B1%5D+=+4r
550+-+6r+=+4r
10r+=+550
r+=+55 mi/hr
check answer:
d%5B1%5D+=+6%2A55
d%5B1%5D+=+330 mi
and
d%5B2%5D+=+4%2A55
d%5B2%5D+=+220 mi
330+%2B+220+=+550 mi
OK