6 cows and 16 ducks

enable’s commence out with what all of us understand. 80 = 2W + L L = 80 – 2W i’m assuming you’re in calculus, otherwise the respond could be stumbled on by trial and blunder. section = L*W = W * (80 – 2W) it is the equation we’d choose for to maximise. section = 80W – 2W^2 Now we take the spinoff. d(section) = 80 – 4W = 0 80 = 4W, so W = 20. Plug that into the 2nd equation L = 80 – 2*(20) = 40 So the section is 20*40 = 800. enable’s verify our answer If the width substitute into 19 as a substitute of 20, what’s the section? L = 80 – 2*(19) = 40 two section = 40 two * 19 = 798. it is smaller than 800. If the width substitute into 21 as a substitute of 20, what’s the section? L = 80 – 2*(21) = 38 section = 38 * 21 = 798. it is smaller than 800. that’s existence choose for to assume that the optimal section with the given volume of fence is 800 cubic meters.