Answer:
P = 21x + 4
Step-by-step explanation:
The perimeter is the length of all the sides added up.
(3x) + (4x + 1) + (2x - 2) + (2x - 2) + (3x + 1) + (4x + 5) + (3x + 1)
3x + 4x + 1 + 2x - 2 + 2x - 2 + 3x + 1 + 4x + 5 + 3x + 1
21x + 1 - 2 - 2 + 1 + 5 + 1
21x + 4
The equation for the perimeter is
P = 21x + 4
1.41 x 10^7 you move the decimal over to the left until you have a number between 1-9
-15 divided by 35 is -0.428...
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.
