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 o

Algebra ->  Linear-equations -> 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 o      Log On


   



Question 1202498: 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 5.7 . See the figure below.
With 54 gallons of fuel in its tank, the airplane has a weight of 2207.8 pounds. What is the weight of the plane with 82 gallons of fuel in its tank?

Found 2 solutions by josgarithmetic, ikleyn:
Answer by josgarithmetic(39625) About Me  (Show Source):
You can put this solution on YOUR website!
The "graph below" might help.

Your description gives something like this:
(x,y) points for x gallons of fuel, y weight of plane in pounds
y=mx+b, for m=5.7; and given point (54, 2207.8).

Directly using the point-slope equation form for a line,
y-2207.8=5.7%28x-54%29.
Do what you want or need from that.

Answer by ikleyn(52852) About Me  (Show Source):
You can put this solution on YOUR website!
.

According to the description, you should add the weight of the additional fuel to 2207.8 pounds.


This additional weight is the difference of volumes in gallons multiplied by the slope coefficient.


So, you write and calculate

    W(82 gallons) = W(54 gallons) + 5.7*(82-54) = 2207.8 + 5.7*(82-54) = 2367.4 pounds.    ANSWER

Solved.

All you need to solve the problem is a bit of common sense.