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.
Answer:
Step-by-step explanation:
Write a function whose k(x) values are 5 more than four times the principal square root of x.
So,
the principal square root of x 
four times the principal square root of x 
5 more than four times the principal square root of x 
Thus,
Answer:
D
Step-by-step explanation:
x + 5 + 3x + C = 180 All triangles have 180 degrees.
4x + 5 + C = 180
But C must be equal to 3x. Notice the markings on the lets of the triangle.
4x + 5 + 3x = 180
7x + 5 = 180 Subtract 5 from both sides
7x = 180 - 5
7x = 175
x = 25
But angle C = 3x
C = 3*25
C = 75
Answer:
$23.8 million
Step-by-step explanation:
w = previous weekends earnings
16.2 = .68w
x = 16.2/0.68
x = 23.8
