Answer:
Step-by-step explanation:
−6x+6−7=2x+8
-1-8=2x+6x
8x=-9
x= -
Answer: x= 5
Step-by-step explanation:
8x+32=1/5(25x−15)−4x
8x + 32 = <u>25x -15</u> - 4x <u><em>- 25x -15/ 5</em></u>
5
8x + 32 = 5x -3 - 4x
8x + 4x - 5x = -32 - 3
7x =-35
x = 35/7
x= 5
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.
