Suppose a home improvement contractor is painting the walls and ceiling of a rectangular room. The volume of the room is 288 cubic feet. The cost of wall paint is $0.06 per square foot and the cost of ceiling paint is $0.16 per square foot. Let x, y, and z be the length, width, and height of a rectangular room respectively. Identify the room dimensions that result in a minimum cost for the paint and use these dimensions to find the minimum cost for the paint. Round your answer to the nearest cent.
Answer:
The minimum cost is $17.30c
Step-by-step explanation:
Given
[tex]V = 288[/tex] --- Volume
[tex]C_1 = 0.06[/tex] --- cost of wall paint
[tex]C_2 = 0.16[/tex] ---cost of ceiling paint
Required
Minimum cost of paint
The volume is calculated as:
[tex]V =xyz[/tex]
Substitute 288 for V
[tex]288 =xyz[/tex]
Make z the subject
[tex]z = \frac{288}{xy}[/tex]
The surface area is calculated as:
[tex]Area = 2(yz + xz) + xy[/tex]
Because xy represent the dimension of the ceiling and the opposite of the ceiling (the floor) will not be painted. Hence, it does not require a coefficient of 2
The cost is:
[tex]C = 0.06 * 2(yz + xz) + 0.16 * xy[/tex]
Substitute [tex]z = \frac{288}{xy}[/tex]
[tex]C = 0.06 * 2(y*\frac{288}{xy} + x*\frac{288}{xy}) + 0.16 * xy[/tex]
[tex]C = 0.06 * 2(\frac{288}{x} + \frac{288}{y}) + 0.16 * xy[/tex]
[tex]C = 0.12(\frac{288}{x} + \frac{288}{y}) + 0.16 * xy[/tex]
[tex]C = (\frac{34.56}{x} + \frac{34.56}{y}) + 0.16 * xy[/tex]
[tex]C = (\frac{34.56}{x} + \frac{34.56}{y}) + 0.16 xy[/tex]
Differentiate w.r.t x and y
[tex]C_x = -\frac{34.56}{x^2} + 0.16y[/tex]
[tex]C_y = -\frac{34.56}{y^2} + 0.16x[/tex]
By comparison: [tex]x = y[/tex]
Set them equal to 0
[tex]C_y = -\frac{34.56}{y^2} + 0.16x=0[/tex]
[tex]-\frac{34.56}{y^2} + 0.16x=0\\[/tex]
Substitute x for y
[tex]-\frac{34.56}{x^2} + 0.16x=0[/tex]
[tex]0.16x=\frac{34.56}{x^2}[/tex]
Cross multiply
[tex]0.16x^3 = 34.56[/tex]
[tex]x^3 = \frac{34.56}{0.16}[/tex]
[tex]x^3 = 216[/tex]
Take the cube root of both sides
[tex]x = \sqrt[3]{216}[/tex]
[tex]x = 6[/tex]
[tex]x=y= 6[/tex]
Substitute 6 for x and for y in [tex]C = (\frac{34.56}{x} + \frac{34.56}{y}) + 0.16 xy[/tex]
[tex]C = (\frac{34.56}{6} + \frac{34.56}{6}) + 0.16 * 6* 6[/tex]
[tex]C = (\frac{2*34.56}{6}) + 5.76[/tex]
[tex]C = 11.52 + 5.76[/tex]
[tex]C = 17.28[/tex]
[tex]C = 17.3[/tex] --- approximated
Help fjdhddjdhdhhdhdhdufh
What is her average?
Answer:
95
Step-by-step explanation:
88 + 95 + 97 + 100 = 380
380 ÷ 4 = 95
To find the average you add all the numbers together and then divide that answer depending on how many numbers there are for example there were 4 numbers in this problem so I divided by 4.
Hoped this helped you!! If you have any other questions about what I said you can ask me :) Have a great day!
You were planning to spend $12 on a
pizza. Write and solve an inequality to represent
the additional amount you must spend to get
free delivery.
Answer:
x+12
Step-by-step explanation:
I belive some part of this may be missing. I feel like their should be more info maybe on how much you have to buy but this in general is technically correct. x is the amount you must spend to get free delivery + 12 bucks
5k + 9 = 89.............
Answer:
k= 16
Step-by-step explanation:
89-9=80
80/5=16
16=k
Answer:
5k+9=89
5k=89-9
5k=80
k=16
(ignore this) question is below.
A square pyramid is shown below.
Which shapes could be formed by slicing the square pyramid by a plane? Select all that apply.
A. circle
B. triangle
C. rectangle
D. trapezoid
E. square
Answer:
B and e
Step-by-step explanation:
The shape is a square.
What is a Square Pyramid?'A square pyramid is a three-dimensional geometric shape having a square base and four triangular faces/sides that meet at a single point (called vertex) is called a square pyramid.'
According to the given problem,
If a square pyramid is cut along the plane, then the cross-section of the solid is square. Because it is a square pyramid.
Hence, we concluded that square could be formed by slicing the square pyramid by a plane.
Learn more about square pyramid here: https://brainly.com/question/27350043
#SPJ2
Rewrite the radical as a rational exponent.
WILL GIVE BRAINLIEST
really need help! anything would be appreciated
find the area of this polygon - PLZZZZZ HELP I WILL GIVE 30 points T^T
Answer:
82 m should be correct i hope
Step-by-step explanation:
8ty grade math, please help.
-Find the volume-
Answer:
47.12389 Rounded is 47.12
Step-by-step explanation:
V=πr2h=π·12·15≈47.12389
Hi hi dude I just don’t want to play anymore I just don’t want to play
9514 1404 393
Answer:
equation: 8 = v + 5solution: v = 3Step-by-step explanation:
The green line is shown as having a length of 8.
The black line is shown as having two parts that add up to the total length of the black line: v + 5.
The problem statement tells you these are the same length. An equation that says they are equal is ...
8 = v + 5
__
This is solved by subtracting 5 from both sides of the equation.
8 -5 = v +5 -5
Combining like terms gives ...
3 = v
The solution is v = 3.
Finding the area of each
Answer:
C.
HOPE THIS HELPS
-Todo <3
Step-by-step explanation:
2*2=4
8x + 9y - 6x - 3y i forgot how to do these lol
solve for x please help asap! 20 points
Answer:
25x-21 would be my best guess!
Find the mean of the sets of data:
2.
12, 67, 34, 10, 78, 78, 49
3. 10,10,13, 13, 45, 21, 67
Answer:
2.) 46.9 3.) 25.6
Step-by-step explanation:
Answer:
2. 46.857
3. 25.571
Step-by-step explanation:
Add all the numbers together and then divide by the number of numbers you added.
12+67+34+10+78+78+49=328
328/7=46.857
10+10+13+13+45+21+67=179
179/7=25.571
Find the measure of 61.
{
839
41
{ K
41 = [?]
Enter
Answer:
m<1 = 97°
Step-by-step explanation:
<1 and 83° are same-side interior angles. Same-side interior angles are supplementary. This implies that:
m<1 + 83° = 180°
Therefore:
m<1 + 83° - 83° = 180° - 83° (subtraction property of equality)
m<1 = 97°
Answer:
<1=97°
steps:
<1+83=180 co interior angle
<1=180-83=97°
Susie is paying $568.97 every month for her $150,000 mortgage. If this is a 30 year mortgage, how much interest will she pay over the 30 years of payments?
Answer:
Step-by-step explanation:
Take the paying multiply by months then take the years - the total loan
so you'd have 568.97(12)30-150000=54829.20
If an image was translated 8 units to the left and 2 units down, what would its rule be?
A. (X,Y-> (X + 8, y - 2)
B. (x, y) --> (X - 8, y - 2)
C. (x, y) --> (X + 8, y + 2)
D. (x, y) --> (X - 8, y + 2)
ill give brainliest! plsss help
Answer:
B
Because u r going -8 units on the x-axis and 2 units down on the y-axis
this dot plot is symmetric, and the data set has no extreme values
Answer:
Where is the plot?
Step-by-step explanation:
Discount, markup, and commission word problems
You might need: Calculator
A store has a 40% off sale on headphones. With this discount, the price of one pair of headphones is $36.
What is the original price of the pair of headphones?
$
Show Calculator
Stuck? Watch a video or use a hint.
Report a problem
Answer:
90$
Step-by-step explanation:
X(40%) = 36$
X(40/100) =36
40X = 3600
X = 90$
(recheck: 90$ x 40%= 36$)
Katie wants to collect over a hundred seashells she already has 34 seashells in her collection each day she finds 12 more seashells on the beach Katie can use fractions of days to find seashells write an equality to determine the number of days D it will take Katie to collect over a 100 seashells. no explanation needed
Answer:
6
Step-by-step explanation:
A line with a slope of 0 passes through the point (9,5). What is its equation in slope-intercept form?
Write your answer using integers, proper fractions, and improper fractions in simplest form.
Answer:
y = 5
Step-by-step explanation:
Any line with a slope of 0 is horizontal, represented by the equation y = a number. That number is the y-value of all the points the line intersects.
We know that that the line intersects (9,5). So, take the y-value of that point and write it into the equation of y = a number. Thus, the answer is y =5.
2. Which pair of angles is not congruent? F. ∠1 and ∠7 G. ∠3 and ∠5 H. ∠4 and ∠6 I. ∠2 and ∠5
Answer:
I) ∠2 and ∠5
Step-by-step explanation:
I'm in the test and need help please
Graph the solution to the following linear Inequality
HELP PLS WUICK! GIVING OUT BRAINLIST
Answer:
27
reason:
did it recently
What is the recursive formula for the geometric sequence 2, 12, 72, 432,.. ?
[tex]a_{1}=2\\a_{n}=6a_{n-1}[/tex]
The recursive formula is aₙ = 2(6)ⁿ⁻¹.
What is recursive formula?A recursive formula for a geometric sequence with common ratio r is given by aₙ = a₁ rⁿ⁻¹ for n≥2.
Given: 2, 12, 72, 432,..
r= 12/2= 6
a= 2
The recursive formula for the nth term,
aₙ = a₁ rⁿ⁻¹
aₙ = 2(6)ⁿ⁻¹
Hence, the recursive formula is aₙ = 2(6)ⁿ⁻¹
Learn more about this concept here:
https://brainly.com/question/11813228
#SPJ1
Write an equation and solve for the missing anglemeasure.
Equation: _______________________
Angle g = ___________
Answer:
Equation: [tex]143 + g = 180[/tex]
[tex]g =37[/tex]
Step-by-step explanation:
Given
The attached figure
Required
The equation to find g and the solution
From the attached: Angles ACD, DCE and ECB lie on a straight line.
Where
[tex]ACD = 90[/tex] [tex]DCE = 53[/tex] [tex]ECB = g[/tex]
This means that:
[tex]ACD + DCE + ECB = 180[/tex]
[tex]90 + 53 + g = 180[/tex]
[tex]143 + g = 180[/tex]
Subtract 143 from both sides
[tex]-143 + 143 + g = 180 - 143[/tex]
[tex]g = 37[/tex]
Which of the following lines is perpendicular to the line 8x + 6y = 12 and passes through the point (-12,-2)?
Answer:
y = 3/4x + 7
Step-by-step explanation:
8x + 6y = 12
6y = -8x + 12
y = -4/3x + 2
Perpendicular slope: 3/4
y - y1 = m(x - x1)
y + 2 = 3/4(x + 12)
y + 2 = 3/4x + 9
y = 3/4x + 7