Problema Solution

Suppose that the weight (in pounds) of an airplane is a linear function of the total amount of fuel (in gallons) in its tank. When graphed, the function gives a line with a slope of 5.8 .

With 55 gallons of fuel in its tank, the airplane has a weight of 2319 pounds. What is the weight of the plane with 87 gallons of fuel in its tank?

Answer provided by our tutors

The total amount of fuel (in gallons) in its tank: x

The weight (in pounds) of an airplane: y

The slope = 5.8

So y = 5.8x + b

x = 55, y  =2319, 5.8*55 + b = 2319, b= 2000

So y = 5.8x + 2000

When x = 87, y = 87*5.8 + 2000 = 2504.6

the weight of the plane with 87 gallons of fuel in its tank is 2504.6 pounds