Answer:
x=1 y = -1/2
(1,-1/2)
Step-by-step explanation:
7x-2y=8
5x+2y=4
I would use elimination since we have 2y in one equation and -2y in the other
7x-2y=8
5x+2y=4
--------------------
12x = 12
Divide each side by 12
12x/12 = 12/12
x =1
The substitute back into equation 2
5(1) +2y = 4
5 +2y = 4
Subtract 5
5-5+2y = 4-5
2y = -1
Divide by 2
2y/2 = -1/2
y = -1/2
Answer:
240 m
Step-by-step explanation:
The area of a square field is 3600 m².
We need to find the length of fencing he needs to buy. It means we need to find the perimeter of the field.
The area of a square field is given by :
A = side²
So,

Length of fencing = perimeter
= 4(s)
= 4(60)
= 240 m
So, he would need to buy 240 m of fencing.
#1 shop A would be cheaper
is there not a graph to this????
Answer:
Maximum area = 800 square feet.
Step-by-step explanation:
In the figure attached,
Rectangle is showing width = x ft and the side towards garage is not to be fenced.
Length of the fence has been given as 80 ft.
Therefore, length of the fence = Sum of all three sides of the rectangle to be fenced
80 = x + x + y
80 = 2x + y
y = (80 - 2x)
Now area of the rectangle A = xy
Or function that represents the area of the rectangle is,
A(x) = x(80 - 2x)
A(x) = 80x - 2x²
To find the maximum area we will take the derivative of the function with respect to x and equate it to zero.

= 80 - 4x
A'(x) = 80 - 4x = 0
4x = 80
x = 
x = 20
Therefore, for x = 20 ft area of the rectangular patio will be maximum.
A(20) = 80×(20) - 2×(20)²
= 1600 - 800
= 800 square feet
Maximum area of the patio is 800 square feet.