Jacob wants to build a rectangular enclosure for his animals. One side of the pen will be against the barn,so he needs no fence on that side.
Let w be the width of the enclosure (perpendicular to the barn) and let l be the length of the enclosure (parallel to the barn).
one side of the length is not counted for perimeter because one side of length will be against the barn.
Perimeter = 400 ft
Perimeter of rectangle = L + W + W
400 = L + 2W
L = 400 - 2W
Area = L * W
Replace L by 400 - 2W
A(W) = (400 - 2W) * W

Now we find out x coordinate of vertex to find the width that maximize the area

a= -2 and b = 400

The width w would maximize the area is w = 100ft
To find maximum area we plug in 100 for W in A(W)


the maximum area is 20,000 square feet
It's the second one for sure
So 6 times 6 is 36 so 36 possibilities and the number that add up to 3 or nine are (2,1; 3,6; 4,5;) so 3 out of 36 or 1 out of 12, the answer is not there
The width would be 236 and the lengths would be 118
Use the equations 2L+W=472 and W*L=MAX
Change the first equation to W=472-2L and plug this into the other equation
(472-2L)(L)=MAX
472L-2L^2=M (take derivative)
472-4L=0 (set to 0 to find the max value)
4L=472
L=118
Plug into original to get W=236
Hope this helps!
300 x 0.02 x 5 = 30
answer
<span> interest will $30 in the first 5 years</span>