Solve the equation for y.
-When going more than 38 miles per hour, the gas mileage of a certain car fits the model $$y = 43.81 - 0.395 x$$ where x is the speed of the car in miles per hour and y is the miles per gallon of gasoline. Based on this model, at what
Speed will the car average 15 miles per gallon? (Round to nearest whole number.)
A) 73 mph
B) 98 mph
C) 149 mph
D) 48 mph

Question

Quizplus · Accepted Answer

To find the speed at which the car averages 15 miles per gallon, substitute $y = 15$ into the equation and solve for $x$:$$15 = 43.81 - 0.395x$$Rearrange the equation to solve for $x$:$$0.395x = 43.81 - 15$$$$0.395x = 28.81$$$$x = \frac{28.81}{0.395}$$$$x \approx 72.94$$Rounded to the nearest whole number, $x = 73$ mph.

Solve the Equation for Y y=43.81−0.395xy = 43.81 - 0.395 xy=43.81−0.395x

Solve the Equation for Y $y = 43.81 - 0.395 x$