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The equation y=−0.0088x2+0.79x+15 models the speed x (in miles per hour) and average gas mileage y (in miles per gallon) for a vehicle. What is the best approximate for the average gas mileage at a speed of 60 miles per hour?

User Gasche
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2 Answers

6 votes

Answer:

30.72 miles per gallon is the best approximate for the average gas mileage at a speed of 60 miles per hour

Explanation:

Given the equation:


y = -0.0088x^2+0.79x+15 ,....[1]

where,

y is the average gas mileage (in miles per gallon)

x is the speed (in miles per hour)

We have to find the the average gas mileage at a speed of 60 miles per hour.


x = 60 miles per hour.

Substitute in [1] we have;


y = -0.0088(60)^2+0.79(60)+15


y = -0.0088(3600)+47.4+15


y = -31.68+47.4+15

Simplify:

y = 30.72 miles per gallon

Therefore, the best approximate for the average gas mileage at a speed of 60 miles per hour is, 30.72 miles per gallon

User Schtever
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8.0k points
5 votes
Answer: 30.72 miles per gallon

To find best approximate for the average gas mileage at a speed of 60 miles per hour you need to replace the variable x with 60. The calculation would be:

y=−0.0088x2+0.79x+15
y= -31.68 +47.4 + 15
y= 30.72
User Edelyne
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8.5k points