SOLUTION: Jane travels to her grandmothers house which is 270km by car. She travels at an average speed of 50km/ hour on good roads and an average speed of 20km/hour on roads under construct

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Question 1145321: Jane travels to her grandmothers house which is 270km by car. She travels at an average speed of 50km/ hour on good roads and an average speed of 20km/hour on roads under construction. If the total trip took 6 hours, find the time it took to travel on the roads under construction, using the substitution or elimination.
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Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
50*g+20*c=270
g+c=6
solve for c
g=6-c
50*g+20*c=270
50*(6-c)+20*c=270