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 6.1 With 45 gallons of fuel in its tank, the airplane has a weight of 2274.5 pounds. What is the weight of the plane with 72 gallons of fuel in its tank?
+9464 We want the equation of a line that has a slope of 6.1 and passes through the point (45, 2274.5) ......here, the fuel = x, and the weight of the plane = y
That will be:
y - 2274.5 = 6.1(x - 45)
We could put this into slope intercept form, but it isn't necessary. We just want to know what y is when x = 72. Plug in 72 for x and solve for y.
y - 2274.5 = 6.1(72 - 45)
y = 6.1(72 - 45) + 2274.5 = 2439.2 pounds
+9464 We want the equation of a line that has a slope of 6.1 and passes through the point (45, 2274.5) ......here, the fuel = x, and the weight of the plane = y
That will be:
y - 2274.5 = 6.1(x - 45)
We could put this into slope intercept form, but it isn't necessary. We just want to know what y is when x = 72. Plug in 72 for x and solve for y.
y - 2274.5 = 6.1(72 - 45)
y = 6.1(72 - 45) + 2274.5 = 2439.2 pounds
