choose a expression that represents three less than seven times a number

Answer:

[tex]-[ln(x^2-yx-y^2)] = K\\[/tex]

Step-by-step explanation:

Given the differential equation [tex](x+2y)y'=2x-y[/tex], this can also be written as;

[tex](x+2y)\frac{dy}{dx} =2x-y[/tex]

On simplification

[tex](x+2y)\frac{dy}{dx} =2x-y\\\\\frac{dy}{dx} = \frac{2x-y}{x+2y} \\\\let \ y = vx\\\frac{dy}{dx} = v+x\frac{dv}{dx}[/tex]

The differential equation becomes;

[tex]v+x\frac{dv}{dx} =\frac{ 2x-vx}{x+2vx}\\\\v+x\frac{dv}{dx} = \frac{ x(2-v)}{x(1+2v)}\\\\v+x\frac{dv}{dx} = \frac{2-v}{1+2v}\\\\x\frac{dv}{dx} = \frac{2-v}{1+2v} - v\\\\x\frac{dv}{dx} = \frac{(2-v)-v(1+2v)}{1+2v}\\\\x\frac{dv}{dx} = \frac{2-v-v-2v^2}{1+2v}\\\\x\frac{dv}{dx} = \frac{2-2v-2v^2}{1+2v}[/tex]

[tex]\frac{dx}{x} = \frac{1+2v}{2-2v-2v^2}dv\\\\integrating\ both \ sides\\\\[/tex]

[tex]\int\limits \frac{dx}{x} = \int\limits \frac{1+2v}{2-2v-2v^2}dv\\\\lnx = \frac{1}{2} \int\limits \frac{1+2v}{1-v-v^2}dv\\\\lnx + C = -\frac{1}{2}ln(1-v-v^2)[/tex]

[tex]C = -\frac{1}{2}ln(1-v-v^2) - lnx \\\\ -ln(1-v-v^2) - 2lnx = 2C\\\\-[ln(1-v-v^2) + lnx^2] = 2C\\\\-[ln(1-v-v^2)x^2] = 2C\\since\ v = y/x\\\\- [ln(1-y/x-y^2/x^2)x^2] = K\\\\-[ln(x^2-yx-y^2)] = K\\[/tex]

Hence the solution to the differential equation is [tex]-[ln(x^2-yx-y^2)] = K\\[/tex]

[tex]\\ \sf\longmapsto \frac{5}{ \sqrt{7} - \sqrt{3} } + \frac{1}{ \sqrt{7} + \sqrt{3} } \\ \\ \sf\longmapsto \frac{5( \sqrt{7} + \sqrt{3} ) + 1 (\sqrt{7} - \sqrt{3} )}{( \sqrt{7} - \sqrt{3} )( \sqrt{7} + \sqrt{3} )} \\ \\ \sf\longmapsto \frac{5 \sqrt{7} + 5 \sqrt{3} + \sqrt{7} - \sqrt{3} }{( { \sqrt{7} )}^{2} - ( \sqrt{3}) {}^{2} } \\ \\ \sf\longmapsto \frac{5 \sqrt{7} + \sqrt{7} + 5 \sqrt{3} - \sqrt{3} }{7 - 3} \\ \\ \sf\longmapsto \frac{6 \sqrt{7} + 4 \sqrt{3} }{4} [/tex]

Answer:

150,000

Step-by-step explanation:

1 m = 100 cm

260 m = 260 * 100 cm = 26000 cm

15 m = 15 * 100 cm = 1500 cm

area of floor = LW = 26000 cm * 1500 cm = 39,000,000 cm^2

area of 1 tile = 26 cm + 10 cm = 260 cm^2

number of tiles needed = 39,000,000/260 = 150,000

Answer: 150,000 tiles

Answer:

Step-by-step explanation:

(D). The locations of A' and B' are A' (0, 6) and B' (6, 0); lines f and f' are parallel.

The location of the points A' and B' after dilation is Option(D) The locations of A' and B' are A' (0, 6) and B' (6, 0); lines f and f' are parallel.

The dilation of a line segment is longer or shorter in the ratio given by the scale factor. If the scale factor is greater than 1, the image of line segment will be larger than the original line, and if the scale factor is less than 1 , the image will be smaller than the original line.

The original line segment is given in the figure with points A and B as A(0,2) and B(2,0) .

When the line segment is dilated by a scale factor of 3, we can draw a parallel line which will be larger than the pre-image of the original line segment.

Also, the new coordinates of the points A and B will also increase by a factor of 3.

Therefore, we have A'(0,6) and B'(6,0) as the new coordinates of the line segment.

Thus, the location of the points A' and B' after dilation is Option(D) The locations of A' and B' are A' (0, 6) and B' (6, 0); lines f and f' are parallel.

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Answer:

D. The z scores are numbers without units of measurement.

Step-by-step explanation:

Z-scores are without units, or are pure numbers.

Answer:

135.7 yd²

Step-by-step explanation:

Surface area of a cone: πr²+πrl, where r = radius and l = slant height

πr²+πrl

= π×3²+π×3×11.4

= 216π/5

= 135.7 yd² (rounded to the nearest tenth)

Answer:

The value of x is 30°

Step-by-step explanation:

We are given that the outer angle of the parallelogram is 60 degrees. Therefore it's respective inner angle will be 180 - 60 = 120 degrees. And, by properties of a parallelogram, the angle opposite to this angle will be 120 degrees as well.

If we draw extend the line creating angle 2x, then we will make ( 1 ) a vertical angle to 2x, ( 2 ) a 90 degree angle, and ( 3 ) and angle that we can let be y. Therefore, 2x + y = 90, and 3x + y = 120.

[tex]\begin{bmatrix}2x+y=90\\ 3x+y=120\end{bmatrix}[/tex] ,

[tex]\begin{bmatrix}6x+3y=270\\ 6x+2y=240\end{bmatrix}[/tex] ,

[tex]6x+2y=240\\-\\\underline{6x+3y=270}\\y=30[/tex],  

[tex]2x + (30) = 90,\\2x = 60,\\x = 30[/tex]

Solution : x = 30°

[tex](f\circ g)(2)=\dfrac{1}{4\cdot2+9}=\dfrac{1}{17}\\\\(f+g)(2)=\dfrac{1}{2}+4\cdot2+9=\dfrac{1}{2}+17=\dfrac{1}{2}+\dfrac{34}{2}=\dfrac{35}{2}[/tex]

Answer:

X= 1/2

Step-by-step explanation:

7^2x+3 =2401

7^(2x+3 )=2401

7^(2x+3 )= 7^4

Taking away the base because its equal to 7

Then solving the power as an equation

2x+3= 4

2x= 4-3

2x= 1

X=1/2

Now substituting x into the equation to know if we are correct

7^(2x+3 )=2401

Where x= 1/2

7^(2*(1/2) +3)= 7^4

7^(1+3)= 7^4

7^4= 7^4

7^4= 2401

Answer:

Step-by-step explanation:

Hello, this is pretty straight forward. Let me remind you the following.

The standard equation of a parabola is

[tex]y=ax^2+bx+c[/tex]

But the equation for a parabola can also be written in "vertex form":

[tex]y=a(x-h)^2+k[/tex]

In this equation, the vertex of the parabola is the point (h,k) .

So, here the vertex is the point (2, -25) and the axis of symmetry is x = 2

Thank you

Answer:

if anyone still needs the answer I added a pic

Step-by-step explanation:

Answer:

27.5

Step-by-step explanation:

3 = 7.5

4 = 10

5*7.5=37.5-10=27.5

Seriously. 2=5 contradicts.

Answer:

Both angle measures and segment lengths.

Step-by-step explanation:

An angle is a shape formed by two rays that meets at a point. The angle is measured by degrees. The angle is formed by the sides of an angle which shares the common endpoint called the vertex. The line is horizontal stretch with a vertical line PQ. It will measure the angle and segments lengths.

Answer:

neither angle measures nor segment lines

Answer:

Step-by-step explanation:

1 km = 0.621 mi

1 hr = 60 min

(5 km)/(4.5 hr) × (0.621 mi)/km × (1 hr)/(60 min) = (0.0115 mi)/min

Answer:

16.50 gallons per minute

Step-by-step explanation:

Because this is a proportional function, we can set up the equation y = kx, where k is the constant of proportionality. By plugging in one point (and this point can be any point provided by the table), we can use the equality k = y/x to find the proportionality constant. If we plug in the information at 1 minute, we get 16.50/1 = 16.5

The constant of proportionality is same for all the rows that is 16.50 gallons per minute.

WE can calculate the Constant of proportionality as;

Constant of proportionality = no of gallons of water per 1 minute.

we have 16.50 gallons of water per 1 minute and 24.75 gallons of water in 1.5 minutes.

In 1 minute, we will have,

24.75 ÷ 1.5 = 16.50 gallons

Similarly,

33 gallons in 2 minutes. In 1 minute, we will have,

33 ÷ 2 = 16.50 gallons.

We can see that there seems to be the same constant of proportionality for the 2nd and 3rd row, that is 16.50.

Thus, a relationship between gallons of water (w) and time (t), considering the constant, 16.50, can be written as:

w = 16.50t

Hence, the constant of proportionality, 16.50, is same for all rows.

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Answer:

Aiko should not have put both of the 'i' out of the brackets.

Step-by-step explanation:

As only one integer has i with it, it is not possible to take the i out of the bracket.

Answer:

(3 1/2, -4)

Step-by-step explanation:

The solution is the point on the graph that the two lines intersect.  The point that the lines intersect in the graph is (3 1/2, -4).

Answer:

3 1/2 , -4

Step-by-step explanation:

yes

Answer:

1.8

Step-by-step explanation:

First, find 40% of 15:

15(0.4)

= 6

Next, find 30% of this:

6(0.3)

= 1.8

So, the answer is 1.8

Answer:

x = 1

Step-by-step explanation:

8x = 5x + 3

Subtract 5x from both sides

8x - 5x = 5x - 5x + 3

Simplify

3x = 3

Divide both sides by 3

3x/3 = 3/3

Simplify

x = 1

Answer:

See below.

Step-by-Step Explanation:

Please refer to the attachment.

If you have any questions, feel free to comment!

Answer:

(-1,-1)

Step-by-step explanation:

theta = -3 pi/4

Changing to degrees =

theta = -3 * 180/4 =-135

x coordinate of -1

The y value would be

= 45

tan 45 = y /1

y = tan 45

y = 1

But we are in the third coordinate so x and y are negative

The coordinates are

(-1,-1)

Step-by-step explanation:

I assume the length that got cut off is 18.

Use Pythagorean theorem:

x² + 36² = (x + 18)²

x² + 1296 = x² + 36x + 324

972 = 36x

x = 27

Answer:

Explained below.

Step-by-step explanation:

In this case we need to test whether the extra carbonation of cola results in a higher average compression strength.

(a)

The hypothesis for the test can be defined as follows:

H₀: The extra carbonation of cola does not results in a higher average compression strength, i.e. μ₁ - μ₂ = 0.

Hₐ: The extra carbonation of cola results in a higher average compression strength, i.e. μ₁ - μ₂ < 0.

(c)

Since the population standard deviations are not provided, we would use the t-test for difference between means.

The test statistic is:

[tex]t=\frac{\bar x_{1}-\bar x_{2}}{\sqrt{\frac{s_{1}^{2}}{n_{1}}+\frac{s_{2}^{2}}{n_{2}}}}[/tex]

  [tex]=\frac{537-559}{\sqrt{\frac{22^{2}}{10}+\frac{17^{2}}{10}}}\\\\=\frac{-22}{8.792}\\\\=-2.502[/tex]

The test statistic value is -2.502.

(c)

Compute the p-value as follows:

[tex]p-value=P(t_{16}<-2.052)=0.012[/tex]

*Use a t-table.

The p-value of the test is 0.012.

(d)

The significance level of the test is, c

p-value = 0.012 < α = 0.05.

The null hypothesis will be rejected.

Conclusion:

The data suggest that the extra carbonation of cola results in a higher average compression strength.

(e)

The assumption necessary for the analysis is:

The distributions of compression strengths are approximately normal.

The correct option is (A).

We know

Sum of two interior angles =exterior angle

[tex]\\ \sf\longmapsto 2x+x=3x[/tex]

[tex]\\ \sf\longmapsto 3x=3x[/tex]

[tex]\\ \sf\longmapsto x=1[/tex]

Answer:

This is a binomial experiment .

Step-by-step explanation:

As the percent is not indicated the success is the amount of percent (if given) say it is 10 % . So p will be equal to = 0.1 and q will be = 1-0.1= 0.9

and n would be five or any number as a binomial experiment is repeated for a fixed number of times.

And x would take any value of n i.e.

X= 0,1,2,3,4,5

If it is 20 % . So p will be equal to = 0.2 and q will be = 1-0.2= 0.8

The probability is the number of the percent indicated. But as it is not indicated we assume it to be 10 % or 20 % .Or suppose any number for it to be a binomial experiment.

The number of trials n would be fixed .

The success remains constant for all trials.

All trials are independent.

Answer:

true

Step-by-step explanation:

Answer: x = 5/3

Step-by-step explanation:

Let the number be x

Then

3x + 4 = 9

3x = 9-4

3x = 5

x = 5/3

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Answer:

The p-value of the test is 0.0023 < 0.02, which means that there is sufficient evidence at the 0.02 level to dispute the company's claim.

Step-by-step explanation:

The company's promotional literature claimed that 28% do not fail in the first 1000 hours of their use.

At the null hypothesis, we test that at least 28% do not fail, that is:

[tex]H_0: p \geq 0.28[/tex]

At the alternative hypothesis, we test if the proportion is of less than 28%, that is:

[tex]H_1: p < 0.28[/tex]

The test statistic is:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.

0.28 is tested at the null hypothesis:

This means that [tex]\mu = 0.28, \sigma = \sqrt{0.28*0.72}[/tex]

Sample of 1800 computer chips revealed that 25% of the chips do not fail in the first 1000 hours of their use.

This means that [tex]n = 1800, X = 0.25[/tex]

Value of the test statistic:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

[tex]z = \frac{0.25 - 0.28}{\frac{\sqrt{0.28*0.72}}{\sqrt{1800}}}[/tex]

[tex]z = -2.83[/tex]

P-value of the test and decision:

The p-value of the test is the probability of finding a sample proportion below 0.25, which is the p-value of Z = -2.83.

Looking at the z-table, z = -2.83 has a p-value of 0.0023.

The p-value of the test is 0.0023 < 0.02, which means that there is sufficient evidence at the 0.02 level to dispute the company's claim.

Answer:

The answer is 0.267949192

Step-by-step explanation:

I hope that is enough numbers.

Answer:

[tex]log_{17}52.875 = log_{10}52.875 : log_{10}17}[/tex]

Step-by-step explanation:

Given

[tex]log_{17}(52.875)[/tex]

Required

Convert to base 10

To do this, we make use of the following logarithm laws;

[tex]log_ba = \frac{log_{10}a}{log_{10}b}[/tex]

In the given parameters;

[tex]a = 52.875[/tex]

[tex]b = 17[/tex]

Substitute these values in [tex]log_ba = \frac{log_{10}a}{log_{10}b}[/tex]

[tex]log_{17}52.875 = \frac{log_{10}52.875}{log_{10}17}[/tex]

Represent as a ratio

[tex]log_{17}52.875 = log_{10}52.875 : log_{10}17}[/tex]

Hence;

[tex]log_{17}(52.875)[/tex] is represented as [tex]log_{17}52.875 = log_{10}52.875 : log_{10}17}[/tex]

Expression  [tex]log_{17} 52.875[/tex] can be written as in form of ratio of log  [tex]\frac{log_{10} 52.875}{log_{10} 17}[/tex] .

Any logarithmic expression [tex]log_{a} b[/tex] can we written as in form of ratio of log on base 10.

                   [tex]log_{a} b=\frac{log_{10} b}{log_{10} a}[/tex]

Here logarithmic expression is,  [tex]log_{17} 52.875[/tex] comparing with above expression.

We get,    [tex]b=52.875,a=17[/tex]

Substitute values of a and b in above expression.

 We get,      [tex]log_{17} 52.875=\frac{log_{10} 52.875}{log_{10} 17}[/tex]

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Answer:

x = 1/2

Step-by-step explanation:

8(-2x+1) =0

Divide each side by 8

-2x+1 = 0

Add 2x to each side

-2x+1+2x = 2x

1 = 2x

Divide by 2

1/2 = 2x/2

1/2 =x

Answer:

1/2

Step-by-step explanation:

8(-2x+1)=0

Use distributive property first

-16x+8=0

Subtract 8 on both sides

-16x=-8

Divide both sides by -16 to get x by itself

x=0.5

Which is also equal to 1/2

Therefore, x is equal to 1/2

Answer:0

Step-by-step explanation:

3x=3xy

x=0

y=0

3 times 0 = 0