Alex, Barry, Charles, David, and Eric paint houses for a living. Alone, Alex can paint an entire house in 24 hours, Barry in 26 hours, Charles in 20 hours, David in 21 hours and Eric in 27 hours. If they work together, approximately how long will it take them to paint 3 houses, rounded to the nearest hour?

Answer: B

Step-by-step explanation:

The line y=2 is solid and shaded above, so it represents [tex]y \geq 2[/tex].

This allows us to eliminate all the options except for B.

a) The resultant force on the particle is equal to - 225 · x, where x is measured in meters.

b) The particle moves with simple harmonic motion.

c) The motion has a period of approximately 1.257 seconds.

d) The particle has an approximate speed of 2.488 meters per second when it is 0.05 metres from C.

e) The equation for the position of the particle is x(t) = 0.5 · cos 25t, where t is in seconds.

In this case we have a system with a particle under periodic motion due to two reactive forces from two springs. a) The system is represented by the following formula based on Newton's laws:

∑F = - k₁ · x - k₂ · x = m · a      (1)

Where:

If we know that k₁ = k₂ = 112.5 N/m, then the resultant force on the particle is equal to - 225 · x, where x is measured in meters.

b) The particle is under simple harmonic motion has a differential equation of the form:

x'' + ω² · x = 0       (2)

Where:

By some algebraic handling on (1), we find the following differential equation:

x'' + [(k₁ + k₂) / m] · x = 0     (3)

Thus, the particle moves with simple harmonic motion.

c) The period of the motion (T), in seconds, is determined by T = 2π / ω. Then, the period is described by the following expression:

T = 2π · √[m / (k₁ + k₂)]

T = 2π · √(9 kg / 225 N /m)

T ≈ 1.257 s

The motion has a period of approximately 1.257 seconds.

d) The speed of the particle (v), in metres per second, can be found by the principle of energy conservation:

(1 / 2) · k · A² = (1 / 2) · k · x² + (1 / 2) · m · v²      (4)

v = √[k · (A² - x²) / m]

Where:

If we know that k = 225 N / m, A = 0.5 m, x = 0.05 m and m = 9 kg, then the speed of the particle is:

v = √[(225 N / m) · [(0.5 m)² - (0.05 m)²] / (9 kg)]

v ≈ ± 2.488 m / s

The particle has an approximate speed of 2.488 meters per second when it is 0.05 metres from C.

e) The function position for a particle under simple harmonic motion:

x(t) = A · cos ω · t      (5)

If we know that A = 0.5 m and ω = 25 rad / s, then the equation for the position of the particle is:

x(t) = 0.5 · cos 25t

The equation for the position of the particle is x(t) = 0.5 · cos 25t.

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The minimum production rate of bushels per acre of corn needed this year is 97 for two year's production to reach the goal of 49,100.

To calculate the minimum production rate for this year, we must subtract the production rate of the previous year, with what is expected to be obtained this year.

Then we must divide the minimum that must be obtained by the total area, by the 300 acres that we have, to know how much corresponds to each acre.

According to the above, each acre must produce 97 bushels of corn to reach the goal of 49,100 for both years.

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Answer:

Step-by-step explanation:

will give brainiest wrrwrwvrwvr

Answer:

x = -34

Step-by-step explanation:

-3x + 2x -34 = 0

sum the x

-3x + 2x = -x

replace -x in the equation

-x -34 = 0

move -34 to other side

-x = 34

divide the two sides by -1 to get x value

x = -34

now replace x value in the equation:

-3(-34) + 2(-34) -34 =

102 -68 -34 =

102 -102 = 0

Answer: Option 1

Step-by-step explanation:

[tex]|x+4|=2\\\\x+4=\pm 2\\\\x=-4\pm 2\\\\x=-6, -2[/tex]

Solve Absolute Value.

| x + 4 | = 2

We know either x + 4 = 2 or x + 4 = −2

x + 4 = 2 (Possibility 1)

x + 4 - 4 = 2 - 4 (Subtract 4 from both sides)

x = -2

x + 4 = −2 (Possibility 2)

x + 4 - 4 = - 2 - 4 (Subtract 4 from both sides)

x = -6

Answer: x = - 2 or x = -6

Therefore we conclude that the solution of the exercise | x + 4 | = 2, is the first number line, since both results are negative.

The sample mean for students with a grade point average of 3.0–4.0 is greater than students with grade point average of 2.0 - 3.0,  the results tend to

From the question, we have the following highlights

From the above highlights, the sample mean for students with a grade point average of 3.0–4.0 is greater than students with grade point average of 2.0 - 3.0

This is because 6.8 is greater than 6.4

This means that Garret's theory about the hours of sleep is correct

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The mean length of the 6 people's index finger is 11.55

The given parameters are:

The mean is calculated as:

[tex]\bar x = \frac{\sum fx}{\sum f}[/tex]

So, we have:

[tex]\bar x = \frac{3 * 9.9 + 3 * 13.2}{3 + 3}[/tex]

Evaluate

[tex]\bar x = \frac{69.3}{6}[/tex]

Divide

[tex]\bar x = 11.55[/tex]

Hence. the mean length of the 6 people's index finger is 11.55

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The resulting coordinates for each row are (-2, 2), (0, 4),()2, 6), (6, 10) and (8,12) respectively

Given the linear function expressed as;

y = x + 4

where

x are the input values and y are the output values

If x = -2

y = -2+4

y = 2

The coordinate (x, y) will be (-2, 2)

If x = 0

y = 0+4

y = 4

The coordinate (x, y) will be (0,4)

If x = 2

y = 2+4

y = 6

The coordinate (x, y) will be (2, 6)

If x = 6

y = 6+4

y = 10

The coordinate (x, y) will be (6,10)

If x = 8

y = 8+4

y = 12

The coordinate (x, y) will be (8, 12)

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Answer:

30 km

Step-by-step explanation:

Distance = rate x time

Distance = 20 x 1.5

Distance = 30

[tex]20*1.5=30[/tex] [tex]km[/tex]

Correct answer:-

Avg. speed = [tex]20km/h[/tex]

Time = [tex]1.5 hour[/tex]

Distance traveled in 1.5 hours is Distance = Speed x Time

So,

[tex]D = 20 * 1.5 = 30.[/tex]

reference link-

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Answer:

Step-by-step explanation:

This is classic right triangle trig, cos specifically. Our reference angle is the one marked 26°, the hypotenuse is given as 12, and the side adjacent to the reference angle is our unknown. This is the cosine ratio. Setting up to solve for x:

[tex]cos26=\frac{x}{12}[/tex] and

12cos(26) = x  Plug this into your calculator in degree mode to get that

x = 10.8

The recursive function o f the given sequence will be an = an-1 + 4

The formula for calculating the recursive function of n arithmetic sequence is expressed as
an = an-1 + d

Determine the common difference

d = 19 - 15 = 23 -19

d = 4

The recursive function o f the given sequence will be an = an-1 + 4

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Answer:

f(n)={n/2     = if n is even=   n={2/2

       {3n+1                                 {3(2)+1   =7

Step-by-step explanation:

if n is even u can put any even no in that place and u can get odd no or even no.(i think)

Answer:

Hope you like it. I have just wrote answers

Using translation concepts, the equation for function g(x) given in the graph is:

[tex]g(x) = 2^{x + 2}[/tex]

A translation is represented by a change in the function graph, according to operations such as multiplication or sum/subtraction either in it’s definition or in it’s domain. Examples are shift left/right or bottom/up, vertical or horizontal stretching or compression, and reflections over the x-axis or the y-axis.

The parent function for this problem is given as follows:

[tex]f(x) = 2^x[/tex]

From the graph, function g(x) was shifted 2 units left, hence x -> x + 2 and the definition is:

[tex]g(x) = 2^{x + 2}[/tex]

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Answer: A

Step-by-step explanation:

The polynomial has roots at [tex]x=-4, -2, 4[/tex].

So, the equation should have factors of [tex](x+4), (x-2), (x-4)[/tex].

This eliminates everything except for A.

Answer:

80°

Step-by-step explanation:

Congruent means the same size, so we know that the angle of the shapes made by the lines HK and GJ are the same, meaning that the angle of GOJ is simply 80°.

Answer is (n + 3) + (n - 7)

Simplified to 2n - 4

Using “n” for number

Answer:

At maximum, she can buy 5 tomatoes.

Step-by-step explanation:

If you solve the inequality, as so:

1.2x+1.8 <=7.8

1.2x <= 6

x <= 5

Answer:

180°

cuz when a line (I forgot the name) and radius meet at the circumference they from an angle of 90°

Using the interpretation of the confidence interval, the correct option is:

We are 95% confident that those who studied had a higher passing rate than those who did not study.

It means that we are x% confident that the population parameter(mean/proportion/standard deviation) is between a and b.

The confidence interval of the difference is:

(0.005, 0.125).

Since the entire interval is positive, the correct option is:

We are 95% confident that those who studied had a higher passing rate than those who did not study.

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This snow flake-like figure can be generated by rotating an end 60° five times around the center of the hexagon. There are two forms: (i) clockwise, (ii) counterclockwise.

Geometrically speaking, snow flakes represent regular hexagons. Regular hexagons can divided into six concentric regular triangles, whose central angles have a measure of 60°. This fractal figure can be generated by rotating 60° five times around the center.

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Answer:

1.894

3.169

2.064

3.690

Step-by-step explanation: 90% ; sample size = 8

Degree of freedom, df = n - 1

t(1 - α/2, 7) = t0.05, 7 = 1.894

The given function has symmetry about the y - axis.

Symmetry of the Function

If we reflect a function's graph about the y-axis, we will get the same graph since if the function is symmetrical about the y-axis. We can reflect a function about the x- and y-axis and obtain the same graph. These two symmetry kinds are known as the even function and odd function.

The given function is,

f(x) = 2x² - 1

It is an even function since the function remains same for both x and -x.

Putting f(x) = 0, we get,

2x² - 1 = 0

2x² = 1

x² = 1/2

x = ±1/2

⇒ Axis of symmetry is, x=0

Hence, the function f(x) is symmetric about y-axis.

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Given the length of both trail, Trail B is 7/4 miles longer than Trail B.

Given that;

To determine how many miles longer is Trail B more than Trail A, we subtract the length of tail A from Tail B.

Trail B - Trail A

17/2 - 27/4

17/2 is the same as; 34/4

34/4 - 27/4

We combine the numerators over common denominator

(34 - 27 )/4

7/4 miles

Given the length of both trail, Trail B is 7/4 miles longer than Trail B.

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[tex]x + y = 55 \\ x - y = 15 \\ \\ 2x = 70 \: \: \: \: \: \: x = 35 \\ y = 55 - x = 55 - 35 = 20[/tex]

Since both np > 5 and n(1 - p) > 5, the normal curve can be used as an approximation to the binomial distribution.

It is the probability of exactly x successes on n repeated trials, with p probability of a success on each trial.

The normal approximation can be used if:

In this problem, the parameters are:

n = 107, p = 0.25.

Hence:

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Answer: [tex]\cos^{-1} \left(\frac{-22}{\sqrt{754}} \right)[/tex]

Step-by-step explanation:

[tex]a \cdot b=(3)(0)+(-4)(5)+(-1)(2)=-22\\\\|a| |b|=\sqrt{3^2 +4^2 +1^2} \sqrt{5^2 +2^2}=\sqrt{754}\\\\\therefore \cos \theta=\frac{-22}[\sqrt{754}}\\\\\theta=\cos^{-1} \left(\frac{-22}{\sqrt{754}} \right)[/tex]

The matrix [tex]\vec C[/tex] resulting from the multiplication between matrices [tex]\vec B[/tex] and [tex]\vec A[/tex] is equal to the matrix [tex]\left[\begin{array}{ccc}37&55&- 20\\23&11&- 20\\25&28&-9\end{array}\right][/tex]. (Correct choice: C)

In this question we must apply the operation of multiplication of two matrices, whose definition is shown below:

[tex]\vec B\, \cdot \, \vec A[/tex], where [tex]\vec B \in \mathbb {R}_{n \times p}[/tex] and [tex]\vec A \in \mathbb{R}_{p \times n}[/tex]     (1)

Where each element of the resulting matrix is equal to the following expression:

[tex]c_{(i, j)} = b_{(i, p)} \,\bullet\, a_{(p, j)}[/tex]     (2)

Where the operator "[tex]\bullet[/tex]" represents a dot product.

Now we proceed to calculate each element of the matrix:

[tex]c_{(1, 1)} = \left[\begin{array}{ccc}5&7&3\end{array}\right] \,\bullet\,\left[\begin{array}{c}1\\5\\- 1\end{array}\right][/tex]

5 · 1 + 7 · 5 + 3 · (- 1)

37

[tex]c_{(1, 2)} = \left[\begin{array}{ccc}5&7&3\end{array}\right] \,\bullet\,\left[\begin{array}{c}7\\2\\2\end{array}\right][/tex]

5 · 7 + 7 · 2 + 3 · 2

55

[tex]c_{(1, 3)} = \left[\begin{array}{ccc}5&7&3\end{array}\right] \,\bullet\,\left[\begin{array}{c}- 3\\1\\- 4\end{array}\right][/tex]

5 · (- 3) + 7 · 1 + 3 · (- 4)

- 20

[tex]c_{(2, 1)} = \left[\begin{array}{ccc}- 3&7&9\end{array}\right] \,\bullet\,\left[\begin{array}{c}1\\5\\- 1\end{array}\right][/tex]

(- 3) · 1 + 7 · 5 + 9 · (- 1)

23

[tex]c_{(2, 2)} = \left[\begin{array}{ccc}- 3&7&9\end{array}\right] \,\bullet\,\left[\begin{array}{c}7\\2\\2\end{array}\right][/tex]

(- 3) · 7 + 7 · 2 + 9 · 2

11

[tex]c_{(2, 3)} = \left[\begin{array}{ccc}- 3&7&9\end{array}\right] \,\bullet\,\left[\begin{array}{c}- 3\\1\\- 4\end{array}\right][/tex]

(- 3) · (- 3) + 7 · 1 + 9 · (- 4)

- 20

[tex]c_{(3, 1)} = \left[\begin{array}{ccc}2&5&2\end{array}\right] \,\bullet\,\left[\begin{array}{c}1\\5\\- 1\end{array}\right][/tex]

2 · 1 + 5 · 5 + 2 · (- 1)

25

[tex]c_{(3, 2)} = \left[\begin{array}{ccc}2&5&2\end{array}\right] \,\bullet\,\left[\begin{array}{c}7\\2\\2\end{array}\right][/tex]

2 · 7 + 5 · 2 + 2 · 2

28

[tex]c_{(3, 3)} = \left[\begin{array}{ccc}2&5&2\end{array}\right] \,\bullet\,\left[\begin{array}{c}- 3\\1\\- 4\end{array}\right][/tex]

2 · (- 3) + 5 · 1 + 2 · (- 4)

- 9

The matrix [tex]\vec C[/tex] resulting from the multiplication between matrices [tex]\vec B[/tex] and [tex]\vec A[/tex] is equal to the matrix [tex]\left[\begin{array}{ccc}37&55&- 20\\23&11&- 20\\25&28&-9\end{array}\right][/tex]. (Correct choice: C)

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