Question

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?
15.7 mi/gal

30.7 mi/gal

61.9 mi/gal

62.9 mi/gal

Answer 1

30.7 mi/gal is The best approximate

Answer 2

we are given

$y=-0.0088x^2+0.79x+15$

where

y is average gas mileage in miles per gallon

x is speed in miles per hour

we have to find average gas mileage at a speed of 60 miles per hour

so, we have

$x=60mph$

now, we can plug it and find y

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

we get

$y=30.72$

so,

the best approximate for the average gas mileage at a speed of 60 miles per hour is 30.7 mi/gal...........Answer