Answer:
15.8
Step-by-step explanation:
Answer:
C(x) = 8*x + 8* (1000)/x + 80
C(x) Domain x > 0
Step-by-step explanation:
enclosed area 1000 ft²
let x be side perpendicular to the river
and y parallel to the river
Then:
A = x*y y = A / x y = 1000/x
Cost of one side (x) 4*x $ then two sides cost = 4*2*x cost = 8*x
Cost of one side (y) 8*y $ 8* (1000/x)
Cost of four cornes posts 4*20 = 80 $
Total cost C(x)
C(x) = 8*x + 8* (1000)/x + 80
R { x > 0}
Taking derivatives both sides of the equation
C´(x) = 8 - 8000/x² C´(x) = 0 8 - 8000/x² = 0
8x² -8000 = 0 x² = 1000
x = 100
(w - 6)(w + 2)
w^2 + 2w - 6w - 12 =
w^2 - 4w - 12 <===
Circumference ≈ 238.76
Area ≈ 4536.46
Step-by-step explanation:
Simplifying
3(3w + -5) = 12
Reorder the terms:
3(-5 + 3w) = 12
(-5 * 3 + 3w * 3) = 12
(-15 + 9w) = 12
Solving
-15 + 9w = 12
Solving for variable 'w'.
Move all terms containing w to the left, all other terms to the right.
Add '15' to each side of the equation.
-15 + 15 + 9w = 12 + 15
Combine like terms: -15 + 15 = 0
0 + 9w = 12 + 15
9w = 12 + 15
Combine like terms: 12 + 15 = 27
9w = 27
Divide each side by '9'.
w = 3
Simplifying
w = 3
