Answer:
a = length of the base = 2.172 m
b = width of the base = 1.357 m
c = height = 4.072 m
Step-by-step explanation:
Suppose we want to build a rectangular storage container with open top whose volume is 12 cubic meters. Assume that the cost of materials for the base is 12 dollars per square meter, and the cost of materials for the sides is 8 dollars per square meter. The height of the box is three times the width of the base. What’s the least amount of money we can spend to build such a container?
lets call a = length of the base
b = width of the base
c = height
V = a.b.c = 12
Area without the top:
Area = ab + 2bc + 2ac
Cost = 12ab + 8.2bc + 8.2ac
Cost = 12ab + 16bc + 16ac
height = 3.width
c = 3b
Cost = 12ab + 16b.3b + 16a.3b = 12ab + 48b² + 48ab = 48b² + 60ab
abc = 12 → ab.3b = 12 → 3ab² = 12 → ab² = 4 → a = 4/b²
Cost = 48b² + 60ab = 48b² + 60b.4/b² = 48b² + 240/b
C(b) = 48b² + 240/b
C'(b) = 96b - 240/b²
Minimum cost: C'(b) = 0
96b - 240/b² = 0
(96b³ - 240)/b² = 0
96b³ - 240 = 0
96b³ = 240
b³ = 240/96
b³ = 2.5
b = 1.357m
c = 3b = 3*1.357 = 4.072m
a = 4/b² = 2.172m
Answer:
1728
Step-by-step explanation:
12*12*12
It is:
40+1+0.3+0.02=41.32
Answer:
576 Units
Step-by-step explanation:
The way your teacher wants you to do it:
1. We know that multiplying a length by four gives us the perimeter of a square.
1a. Thus, we multiply the given length by four. 4(10x+4)=40x+16
1b. We know the perimeter is 96. So: 40x+16=96
2. Solving for x, we get x=2
3. Plugging our solved x into the given length (10x+4), we see that the length of a side of the square is 10*2+4=24.
4. We know that the area of a square can be found by squaring the side of a square.
4a. 24*24=576.
5. The area is 576 units.
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Easier Solution:
1. We know that the perimeter is length*4.
2. We set L to length.
2a. 4L=96
2b. L=24
3. We know that the length square is area.
4. 24*24=576.
Answer:
The area is approximately 453 ft²
Step-by-step explanation:
Area of a circle = 
If
= 22/7, and r = 12 ft
Area = (22/7)×12²
= 3.143*144
= 452.592 ft²
≈ 453 ft²