Answer:
400 m^2.
Step-by-step explanation:
The largest area is obtained where the enclosure is a square.
I think that's the right answer because a square is a special form of a rectangle.
So the square would be 20 * 20 = 400 m^2.
Proof:
Let the sides of the rectangle be x and y m long
The area A = xy.
Also the perimeter 2x + 2y = 80
x + y = 40
y = 40 - x.
So substituting for y in A = xy:-
A = x(40 - x)
A = 40x - x^2
For maximum value of A we find the derivative and equate it to 0:
derivative A' = 40 - 2x = 0
2x = 40
x = 20.
So y = 40 - x
= 40 - 20
=20
x and y are the same value so x = y.
Therefore for maximum area the rectangle is a square.
Box 1:0,3,6,9,12, Box 2: 0,1,2, 14. Box3:1,9,13,18, box4:4,5,7hope this helps
30 times 86 equals 2580 and 4 times 86 equals 344 add those together and you get 2924
To figure this out you first find the difference between -18 and 60, which is 78 you then just divide, 78/4.5 which is approximately 17.55 mins or 17.6 rounded.
