X + y = 2 —> y = 2 - x
insert to first equation
2-x=x^2-3x-6
x^2 - 3x - 6 - 2 + x = 0
x^2 - 2x - 8 = 0
(x-4)(x+2) = 0
x = 4 or x = -2
36% = 36/100 divide both numerator and denominator by 4 gives you 9/25
50% is equal to 5/10 so 5/10 were party cakes 1/5x2=2/10 so 2/10 were fruit cakes 5/10+2/10=7/10 so 10/10 which is 100% of all cakes 10/10-7/10=3/10 so 3/10 of the cakes were sponge cakes.
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.