Let x represent the length of the side of the pen that is parallel to the barn. Then the area (y) will be
.. y = x(300 -x)/2
This describes a downward opening parabola with zeros at x=0 and x=300. The vertex (maximum) will be found at the value of x that is halfway between those, x = 150.
For that value of x, the pen area is
.. y = 150(300 -150)/2 = 150^2/2 = 11,250 . . . . . square feet.
The answer is 66.
Explanation
4×3 = 12,
6×9 = 54.
54+12 = 66
To do this the first box on the left corner it says three and four so you multiply them. Then there’s a second box with six and nine. You have to multiply 6 and 9 together. After you get those answers you add that answer with the answer from three times four.
Hope I helped you!
:)
plug in 6 for x and 17 for y
so, 4(6)+5(17)=109