The smallest amount of material needed is 54 square centimeters
<h3>How to determine the amount of material needed?</h3>
The given parameters are:
Volume = 36 cubic centimeters
Represent length with x, width with y and height with z.
So, we have
x = 3y
The volume is calculated as:
V = xyz
This gives
V = 3y²z
Substitute 36 for V
3y²z = 36
Divide by 3
y²z = 12
Make z the subject
z = 12/y²
The surface area is:
S = 2(xy + xz + yz)
This gives
S = 2(3y² + 3yz + yz)
Evaluate the like terms
S = 2(3y² + 4yz)
Expand
S = 6y² + 8yz
Substitute z = 12/y²
S = 6y² + 8y * 12/y²
This gives
S = 6y² + 96/y
Differentiate
S' = 12y - 96/y²
Set to 0
12y - 96/y² = 0
Multiply through by y²
12y³ - 96 = 0
Add 96 to both sides
12y³ = 96
Divide by 12
y³ = 8
Take the cube root of both sides
y = 2
Recall that:
x = 3y and z = 12/y²
This gives
x = 3 * 2 = 6
z = 12/2² = 3
Recall that:
S = 2(xy + xz + yz)
So, we have:
S = 2(6 * 2 + 3 * 3 + 2 * 3)
Evaluate
S = 54
Hence, the smallest amount of material needed is 54 square centimeters
Read more about surface areas at:
brainly.com/question/76387
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Answer:9
Step-by-step explanation: x+4=13
x=13-4
x=9
Answer: 20 cups of grape juice are needed for 8 cups of peach juice.
Step-by-step explanation:
5 times 4 is 20.
We must do this step because you need 2 cups for 1 batch, and times 4 that is 8. So then we multiplied 5 times 4.
So, 20 cups of grape juice are needed for 8 cups of peach juice.
Hope this answer helps you out!
The line crosses the y-axis at y=4, so will have an equation of the form
... y = (something)·x + 4
The line rises from left to right, so has a positive slope. That is, the "(something)" must be greater than zero.
The only selection that meets these criteria is
... B y = 2x + 4
