Answer:
- Base Length of 84cm
- Height of 42 cm.
Step-by-step explanation:
Given a box with a square base and an open top which must have a volume of 296352 cubic centimetre. We want to minimize the amount of material used.
Step 1:
Let the side length of the base =x
Let the height of the box =h
Since the box has a square base
Volume, 
Surface Area of the box = Base Area + Area of 4 sides
Step 2: Find the derivative of A(x)
Step 3: Set A'(x)=0 and solve for x
![A'(x)=\dfrac{2x^3-1185408}{x^2}=0\\2x^3-1185408=0\\2x^3=1185408\\$Divide both sides by 2\\x^3=592704\\$Take the cube root of both sides\\x=\sqrt[3]{592704}\\x=84](https://tex.z-dn.net/?f=A%27%28x%29%3D%5Cdfrac%7B2x%5E3-1185408%7D%7Bx%5E2%7D%3D0%5C%5C2x%5E3-1185408%3D0%5C%5C2x%5E3%3D1185408%5C%5C%24Divide%20both%20sides%20by%202%5C%5Cx%5E3%3D592704%5C%5C%24Take%20the%20cube%20root%20of%20both%20sides%5C%5Cx%3D%5Csqrt%5B3%5D%7B592704%7D%5C%5Cx%3D84)
Step 4: Verify that x=84 is a minimum value
We use the second derivative test
Since the second derivative is positive at x=84, then it is a minimum point.
Recall:
Therefore, the dimensions that minimizes the box surface area are:
- Base Length of 84cm
- Height of 42 cm.
Answer:
a) 3,6,9,12,15,18,21,24
b) 8,16,24,32,48,56,64,72
a) 16
b) 48
c) 24
d) 36
Step-by-step explanation:
Answer: the first answer is 72
Step-by-step explanations
24x3=72
Answer:
the equation D ) would cause a consistent-independent system.
Step-by-step explanation:
A ) 5 x + y = 7 /*( -2 )
10 x + 2 y = 14
--------------------
- 10 x - 2 y = - 14
10 x + 2 y = 14
------------------------
0 x = 0 ( Dependent system )
B ) 5 x + y = 7 / * 3
- 15 x - 3 y = - 6
--------------------------
15 x + 3 y = 21
- 15 x - 3 y = - 6
-------------------------
0 x = 15 ( Inconsistent system )
C ) 5 x + y = 7
5 x + y = - 7 / * ( - 1 )
---------------------------
5 x + y = 7
- 5 x - y = 7
------------------
0 x = 14 ( Inconsistent system )
D ) 5 x + y = 7 / * ( - 2 )
6 x + 2 y = 7
------------------
- 10 x - 2 y = - 14
6 x + 2 y = 7
-----------------------
- 4 x = - 7; x = 7/4; y = - 7/4
Answer:
34
Step-by-step explanation:
$1.25 = 125 cents.
$42 = 4200 cents
Tickets sold at 75 cents = x
Tickets sold at 125 cents = y
x + y = 40
75x + 125y = 4200
Multiply the first equation by 75
75x + 75y = 3000
75x + 125y = 4200
Subtract the the second equation from the first.
75x + 75y = 3000
- 75x + 125y = 4200
-------------------------------
0 - 150y = - 1200
Divide both sides by - 150
-150y/-150 = -1200/-150
y = 8
Substitute y = 8 into the first equation
x + y = 42
x + 8 = 42
x = 42 - 8
x = 34
34 tickets were sold for 75 cents
8 tickets were sold for $1.25
