SOLUTION: You travel 575 miles in 8 hours. Part of the trip is made at 60mph and part of the trip is made at 80mph. Find the time traveled at each rate. This is the question. I have that d

Question 96328This question is from textbook
: You travel 575 miles in 8 hours. Part of the trip is made at 60mph and part of the trip is made at 80mph. Find the time traveled at each rate. This is the question. I have that distance =rate * time and 575=r*8. I also have that r=(60T+80t)/2 and T+t=8 but when i try to solve it I get a negative time. Thanks for trying to help. This question is from textbook

Found 2 solutions by checkley71, Earlsdon:
Answer by checkley71(8403) (Show Source): You can put this solution on YOUR website!
575=60T+80(8-T)
575=60T+640-80T
575=-20T+640
-20T=575-640
-20T=-65
T=-65/-20
T=3.25 HOURS DRIVING @ 60MPH.
8-3.25=4.75 HOURS DRIVING @ 80MPH.
PROOF
575=60*3.25+80*4.75
575=195+380
575=575

Answer by Earlsdon(6294) (Show Source): You can put this solution on YOUR website!
You are taking the right approach! Let's see how it goes:
and...
We are given that:

or
and we have to find:
and but we also know that:
or
Let's put in some values.
or

Now, since we can write:
Solve this for

substitute
Solve this for

hours.

hours.
Check:
The total trip distance.
= 575
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