Only 20%of earths water is useable
Answer:
The slope of the line is
.
Step-by-step explanation:
We use the formula change in y over change in x to find the slope:

Then we simplify:

The slope of the line is
.
Im not sure but i found the answer as n= 52
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:
<h2>А. 3, 5, 7</h2><h2 />
Step-by-step explanation:
Because
7 - 3 = 4
7 + 3 = 10
then
7 - 3 < 5 < 7 + 3
the 3 other cases don’t fit with this rule.