Mark made a business trip of 259.5 miles. He averaged 59 mph for the first part of the trip and 57 mph for the second part. If the trip took 4.5 hours, how long did he
travel at each rate?

Respuesta :

Answer: He spends 1.5 hours on the first part of trip and 3 hours on the second part of trip

Step-by-step explanation:

Let x = the number of hours for first part

Let y = the number of hours for second part

Concept: speed × time = distance

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x+y=4.5

59x+57y=259.5

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y=4.5-x

59x+57y=259.5

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59x+57(4.5-x)=259.5

59x+256.5-57x=259.5

2x+256.5=259.5

2x=3

x=1.5

4.5-1.5=3 hrs

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