Answer:
[tex]x {}^{2} - 2x - 1 = 14 \: where \: x = 5[/tex]
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
Which are values of dimes and nickels?
write each power as a product of the Same factor then find the value 1. 4^3 2. 2^6 3. 8^4 4. 12^2
Answer:
15^3=15×15×15=3375
0^4=0×0×0×0=0
5^5=5×5×5×5×5=3125
3.5^2=3.5×3.5=12.25
6^5=6×6×6×6×6=7776
7^4=7×7×7×7=2401
1^8=1×1×1×1×1×1×1×1=1
2.5^3=2.5×2.5×2.5=15.625
Step-by-step explanation:
Help me answer the question
Answer:
cubic
Step-by-step explanation:
you can eliminate all of the other ones
Answer:
cubic
Step-by-step explanation:
quadratic = makes a parabola - U shaped
linear = makes a straight line
cubic = makes a shape just like the one in the picture
square root = makes a curved shape and its also a shape that looks like half of a parabola lying on its side
5. A large firm hires 3% more workers which brings
its total number of workers to 12772. How many
workers did the firm have before the increase?
Answer:
425733.32
Step-by-step explanation:
3%= 12772×100÷x
3x= 12772×100
x=425733.34
Help fjdhddjdhdhhdhdhdufh
Find y to the nearest hundredths place
Answer:
I cant see the picture
Step-by-step explanation:
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
I'm in the test and need help please
Graph the solution to the following linear Inequality
What are the x-intercepts of the graph of y = x + 7x + 10?
O A. (5,0) and (2.0)
O B. (-7,0) and (-10,0)
O c. (7,0) and (10,0)
O D. (-5,0) and (-2, 0)
Answer:
D
Step-by-step explanation:
I hope this helps a bit.
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:
FREE BRAINLIST NEED HELP ASAP
Jamal gets ready for a basketball game by shooting 101010 free-throws. Based on previous data, he has a 70% chance of making each free-throw. Assume that the results of each free-throw are independent.
Which of the following would find the probability of Jamal making exactly 8 of 10 free-throws?
A) (10
7) (0.70)^7(0.30)^3
B) (10
8) (0.70)^8(0.30)^2
C) (10
8) (0.70)^2(0.30)^8
D) (70
10) (0.70)^8(0.30)^2
E) (0.70)^8(0.30)^2
Answer: you’re welcome
Step-by-step explanation:
The probability for the given case is ⁰C₈(0.8)⁸(0.3)². The correct option is (c).
How to find probability using binomial distribution?The binomial distribution is based on the binomial theorem which can be written as (a + b)ⁿ = ⁿC₀aⁿb⁰ + ⁿC₁aⁿ⁻¹b¹ + ⁿC₂aⁿ⁻²b²+ ....+ ⁿCₙa₀bⁿ.
In order to use in the probability, there should be events independent of each other and the sum of there probabilities is 1.
Given that,
The probability of making free-throw is 70% = 70/100 = 0.7
Then, the probability of not making free-throw is 1 - 0.7 = 0.3.
The exact 8 free-throws out of 10 implies that there will be 2 throws that are not free.
So, this case belongs to the binomial distribution which can be written as,
ⁿCₓpˣqⁿ⁻ˣ, where p is the probability of success and q is the probability of failure, n is the total number of trials and x is the number of favorable trials.
Now, in order to find the probability of exact 8 free-throws out of 10 can be found using binomial distribution as follows,
P (exact 8 throws) = ¹⁰C₈(0.8)⁸(0.3)²
Hence, the probability of getting exact 8 free-throws out of 10 is ¹⁰C₈(0.8)⁸(0.3)².
To know more about binomial distribution click on,
https://brainly.com/question/14565246
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Find the solution(s) to the system of equations below:
3x - 5y = 3 and y = 3x2 - 4x + 1
Answer:
The solutions I found to this system of equations are (1, 0) and (⁸/₁₅, -7).
I keep second guessing and recalculating the second point there, so I'd suggest double-checking it by going through the work yourself. The first one checks out though.
Step-by-step explanation:
Let's solve this by substitution, where one equation is solved for one variable and substituted in to the other. As the latter equation is already solved for y, we can simply substitute it into the other:
given:
y = 3x² - 4x + 1
3x - 5y = 3
then:
3x - 5(3x² - 4x + 1) = 3
Which we can then simplify and solve:
3x - 15x² + 20x - 5 = 3
-3x + 15x² - 20x + 5 = -3
15x² - 23x = -8
Now we can find find the solution by completing the square:
15(15x² - 23x) = 15(-8)
225x² - 345x = -120
225x² - 345x + (23/2)² = -120 + (23/2)²
225x² - 345x + 529/4 = -120 + 529/4
(15x - 11.5)² = -120 + 132.25
(15x - 11.5)² = 12.25
15x - 11.5 = ± √12.25
15x - 11.5 = ± 3.5
15x = 11.5 ± 3.5
x = (11.5 ± 3.5) / 15
x = 15 / 15, and 8 / 15
x = 1, and 0.5333...
Now that we have x, we can solve for y.
given: 3x - 5y = 3
for x = 1:
3 - 5y = 3
y = 0
for x = ⁸/₁₅:
3(⁸/₁₅) - 5y = 3
5y = 3(⁸/₁₅) - 3
5y = ²⁴/₁₅ - ⁴⁵/₁₅
5y = -²¹/₁₅
y = -²¹/₃
y = -7
So the solutions to this system of equations are (1, 0) and (⁸/₁₅, -7).
(ignore this) question is below.
Find the volume of a pyramid with a square base, where the side length of the base is 10.6\text{ in}10.6 in and the height of the pyramid is 12.3\text{ in}12.3 in. Round your answer to the nearest tenth of a cubic inch.
Answer:
460.7
Step-by-step explanation:
Answer:
460.7
Step-by-step explanation:
it just 460.7
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.
there are 640 students in one school. How many boys are there if it is known that 1/4 of the number of girls is equal to one sixth of the number of boys?
Answer:
960
Step-by-step explanation:
You have to figure out what 1/4th of 640 is, which is 160.
It says that number is 1/6th of boys, so you multiply by the inverse.
160x6 = 960
well since all of the girls = 4/6ths of the boys that would mean 24/24girls=16/24boys
16/24 is 66.666666666667% of 24/24
66.666666666667% of 640 is426.666666667 but in my head i would round up so:
Approximately
427 boys and 213 girls.
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
Find the equation of the straight line passing through the point (-4,5) and perpendicular to the line y=2x+7.Suppose the equation is y=cx+d.Find c,d.
Answer:
The equation of the line is:
[tex]y = -\frac{1}{2}x + 3[/tex]
Step-by-step explanation:
Equation of a line:
The equation of a line has the following format:
[tex]y = mx + b[/tex]
In which m is the slope and b is the y-intercept.
Perpendicular lines:
If two lines are perpendicular, this means that the multiplication of their slopes is -1.
Perpendicular to y=2x+7
This means that:
[tex]2m = -1[/tex]
[tex]m = -\frac{1}{2}[/tex]
So
[tex]y = -\frac{1}{2}x + b[/tex]
Passing through the point (-4,5)
This means that when [tex]x = -4, y = 5[/tex]. We use this to find b.
[tex]y = -\frac{1}{2}x + b[/tex]
[tex]5 = -\frac{1}{2}(-4) + b[/tex]
[tex]2 + b = 5[/tex]
[tex]b = 3[/tex]
The equation of the line is:
[tex]y = -\frac{1}{2}x + 3[/tex]
SOMEONE PLEASE HELP NO LATE RESPONSES JUST PLEASE ASAP
Answer:
93.5
Step-by-step explanation:
slope of the line perpendicular to the line whose equation is −2x + y = −3
Answer:
What is the slope of a line perpendicular to the line whose equation is 2x+y=3?
Step-by-step explanation:
-1/2
Step-by-step explanation:
perpendicular slopes are the opposite reciprical
so you basically flip it and change the sign
I hope this helps :)
Answer:B
Step-by-step explanation:
2 Write 3 x 10 in standard notation.
Answer:
30
Step-by-step explanation:
3 x 10 = 30
add the 0 from ten to 3 and you get 30
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]
Concept Recall #2: (6.RP.A.1)
There are 14 girls and 15 boys in a sixth grade math class.
Write this relationship as a ratio.
Answer:
b
Step-by-step explanation:
Answer:
B is the correct answer
Step-by-step explanation:
Hope this helps
1. Solve the following equation for all values of x.
10x2 – 5x=0
Answer:
20=0+5x
x=20/5
x=4
x=4
x=4
Answer:
exact form:
x=0, 1/2
decimal form:
x=0, 0.5
What number is 40% of 720
Answer:
the answer should be 288
Answer:
288
Step-by-step explanation:
To solve this, you divide 40% by 100.
= (40% / 100) x 720
Then you multiply 0.4 by 720.
= 0.4 x 720
= 288
What is the measure of ∠B?
A is 28 degrees
C is 36 degrees
Answer:
The measure of angle B is 116
Step-by-step explanation:
Answer:
B=118 degrees
Step-by-step explanation:
All triangles are meant to be exactly 180 degrees. So 180 - (28 +36) =B =118 degrees
many 2/3 are in 9/8?"
Answer:
1.6875 2/3's are in 9/8.
Step-by-step explanation:
(9/8)/(2/3)=1.6875
Please help me as soon as possible I need it now please be serious thank you
Answer:
x+6y+18=0.
Step-by-step explanation: