What value of coefficient b makes the equation true for any real number x?

The values of [tex]D, D_x, D_y[/tex] are, [tex]D = 13, D_x = 8, D_y = 19[/tex].

What is Cramer's rule?

One of the key techniques used to solve an equation system is Cramer's rule. The determinants of matrices are used in this method to derive the values of the system's variables. Thus, the determinant technique is another name for Cramer's rule.

Consider, the given system of equations

-3x + 4y = 4             ...(1)

2x = 7y - 9               ...(2)

equation (2) can be written as,

2x - 7y = -9             ..(3)

Using Cramer's rule, we have to find the determinant of the coefficient matrix

matrix,

D= [tex]\left[\begin{array}{ccc}-3&4\\2&-7\end{array}\right][/tex]  = (-3)(-7) - 8 = 21 - 8 = 13

Secondly, find the determinant of x coefficient matrix,

[tex]D_x[/tex] =  [tex]\left[\begin{array}{ccc}4&4\\-9&-7\end{array}\right][/tex] = (4)(-7) - (4)(-9) = -28 + 36 = 8

Similarly, find the determinant of y coefficient matrix,

[tex]D_y[/tex] = [tex]\left[\begin{array}{ccc}-3&4\\2&-9\\\end{array}\right][/tex] = (-3)(-9) - (4)(2) = 27 - 8 = 19

Hence, values of the determinants are, [tex]D = 13, D_x = 8, D_y = 19[/tex].

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Answer:

-x^5+2x³-x²-1x-1

Step-by-step explanation:

First order the terms based on highest degree or exponent.

-x^5+2x³-x²-3x¹+2x-1

Next combine like terms.

-3x¹ is simply -3x so -3x+2x = -1x

-x^5+2x³-x²-1x-1

Answer:

Nick

Step-by-step explanation:

Nick: 39 miles / 2 hours = 19.5 miles per hour

Jane: 34 miles / 5 hours = 6.8 miles per hour

Nick is biking faster!

a) The expected value of each $1 bet in roulette is of: -$0.988.

b) The interpretation is given as follows: Over time, you should expect to lose about 999 cents for every dollar you bet.

The expected value of a discrete distribution is obtained as the sum of each outcome multiplied by it's respective probability.

The three-number bet is when one sequence of three numbers has to be correctly chosen, hence the probability of winning is of:

p = 1/(10³) = 1/1000.

(as there is only one correct sequence, and for each number, there are 10 outcomes).

The payout is given as follows:

11:1.

That is, if you win, you earn 11 times the amount you bet.

Considering a bet of $1, the distribution of earnings is given as follows:

Hence the expected value of the bet is:

E(X) = 11/1000 - 999/1000 = -$0.988.

Which is the amount you are expected to lose for every dollar you bet.

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The statement that are correct from the graph is:

Some input values are negative.

some output values are negative.

Some input values are integers.

Some output values are integers.

From the graph:

The x value is -2,-4 that is negative.

so the some inputs are negative.

Y has values -2 ,-4 which are negative.

So the some outputs are negative.

The point values from the graph is -4,-2,0,2,4 which belong to integers.

So some input values and output values are integers.

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g(x) is a vertical dilation of f(x), then the x-value of the vertex does not change, using that we will see that the vertex of g(x) is (-4, 24)

We know that there is a parabola graphed called f(x), such that the vertex of f(x) is at (-4, 6).

We also have a vertical dilation of this function defined as:

g(x) = 4*f(x)

Notice that because this is a vertical dilation, the x-value of the vertex does not change, then the vertex is at x = -4, like on f(x).

Evaluating there we get:

g(-4) = 4*f(-4)

And because the vertex of f(x)  is (-4, 6), then we know that:

f(-4) =6

Replacing that we get:

g(-4) = 4*f(-4) = 4*6 = 24

Then the vertex of g(x) is at (-4, 24)

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The joint relative frequency of students who use a mobile device in an online class is approximately 32%.

The joint relative frequency of students who use a mobile device in an online class, we need to divide the frequency of the intersection of the "Mobile device" and "Online" categories by the total number of students (200 in this case) and express it as a percentage.

From the given two-way frequency table, we can see that the frequency for the intersection of "Mobile device" and "Online" is 64.

The joint relative frequency can be calculated as:

Joint Relative Frequency = (Frequency of intersection / Total number of students) × 100

Joint Relative Frequency = (64 / 200) × 100

Joint Relative Frequency ≈ 32%

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The percentage of pediatricians that work more than 70 h per week is; 2.275%

The formula for z-score of a normal distribution is;

z = (x' - μ)/σ

where;

x' is sample mean

μ is population mean

σ is standard deviation

We are given;

sample mean; x' = 70 hours

population mean; μ = 40 hours

standard deviation; σ = 15 hours

Thus;

z = (70 - 40)/15

z = 2

From online p-value from z-score calculator, we have;

p-value =  0.02275 = 2.275%

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Answer:

[tex]10\sqrt{6}[/tex] feet by [tex]\frac{20}{3}\sqrt{6}[/tex] ft

Step-by-step explanation:

If the length is [tex]l[/tex], then the width is [tex]\frac{2}{3}l[/tex].

Using the formula for the area of a rectangle,

[tex]l \cdot \frac{2}{3}l=400 \\ \\ \frac{2}{3}l^2=400 \\ \\ l^2=600 \\ \\ l=10\sqrt{6}[ \\ \\ \implies w=\frac{20}{3}\sqrt{6}[/tex]

Answer:

First by using inverse operations, subtract 12 on both sides.

Now it will become

Now divide 6 to isolate x

Hence, the answer is

Answer: 12

Step-by-step explanation: When multiplying (in this case finding a product,) by one, the number you are multiplying will always be the answer.

The percent represented by the shaded area as in the task content is; 40%.

It follows from the task content that the percent of the whole that is shaded as in the task content be determined.

By observation, the whole is partitioned into 5 parts with 2 parts shaded.

Consequently, when expressed as a fraction; the shaded region is; 2 / 5 of the whole.

Ultimately, when expressed as a percentage, the shaded region is;

( 2 / 5 ) × 100% = 0.4 × 100%

= 40%.

Ultimately, the percent of the whole that is shaded is; 40%.

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Based on the perimeter of this isosceles triangle, the possible x-coordinate for point L is either -16.85 or 10.85.

In Mathematics, the perimeter of an isosceles triangle can be determined by summing up all of its side lengths that encloses. Mathematically, the perimeter of isosceles triangle JKL is given by this mathematical expression:

Perimeter, P = JK + JL+ KL

36 = JK + JL+ KL

Next, we would determine the distance between each vertices by using this formula:

Distance = √[(x₂ - x₁)² + (y₂ - y₁)²]

Distance JK = √[(-3 - (-3))² + (-9 - 7)²]

Distance JK = √0 + 256

Distance JK = √256

Distance JK = 16

Distance JL = √[(-9 - (-1))² + (-3 - x)²]

Distance JL = √8² + (-3 - x)²

Distance JL = √64 + (-3 - x)²

Distance KL = √[(7 - (-1))² + (-3 - x)²]

Distance KL = √8² + (-3 - x)²

Distance KL = √64 + (-3 - x)²

Note: Side JK is equal to side KL as an isosceles triangle.

From the perimeter of this isosceles triangle, we have:

36 = JK + JL+ KL

36 = 16 + JL+ JL

2JL = 20

JL = 10 units.

Now, we can determine the possible x-coordinate for point L:

256 = 64 + (-3 - x)²

256 - 64 = (-3 - x)²

192 = (-3 - x)²

13.85 = -3 - x

x = -3 ± 13.85

x = (-3 -  13.85) or (-3 + 13.85)

x = -16.85 or 10.85

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1. The hypothesis are given as follows:

2. The critical value is of: t = 2.3974.

3. The test statistic is of: t = 2.35.

4. The decision is: Reject the null hypothesis.

5. The conclusion is: There is enough evidence to conclude that the mean is greater.

At the null hypothesis, it is tested if there is not enough evidence to conclude that the mean in Los Angeles is greater, that is:

[tex]H_0: \mu \leq 178258[/tex]

At the alternative hypothesis, it is tested if there is enough evidence, hence:

[tex]H_1: \mu > 178258[/tex]

The t-distribution is used, as we have the standard deviation for the sample but not for the population. Using a t-distribution calculator, with 55 - 1 = 54 df, a right-tailed test, as we are testing if the mean is greater than a value and a significance level of 0.01, the critical value is:

t = 2.3974.

Hence the decision rule is defined as follows:

The test statistic is given by the equation presented as follows:

[tex]t = \frac{\overline{x} - \mu}{\frac{s}{\sqrt{n}}}[/tex]

The parameters are listed as follows:

In the context of this problem, the values of these parameters are given as follows:

[tex]\overline{x} = 191790, \mu = 178258, s = 42627, n = 55[/tex]

Hence the value of the test statistic is:

[tex]t = \frac{\overline{x} - \mu}{\frac{s}{\sqrt{n}}}[/tex]

[tex]t = \frac{191790 - 178258}{\frac{42627}{\sqrt{55}}}[/tex]

t = 2.35.

The test statistic is greater than the critical value, hence:

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The equation of the line that passes through the point (−7,−4) with slope 10/7 is y = (10/7)x + 6

The coordinates of the point = (-7, -4)

The slope of the line = 10/7

The slope intercept form is

y = mx + b

Where m is the slope of the line

b is the y intercept

The point slope form is

[tex]y-y_1=m(x-x_1)[/tex]

Where [tex](x_1,y_1)[/tex] is the coordinates of the point

Substitute the values in the equation

y -(-4) = 10/7(x - (-7))

y + 4 = (10/7)(x + 7)

Convert to slope intercept form

y +4 = (10/7)x + 10

y = (10/7)x + 10 - 4

y = (10/7)x + 6

Hence, the equation of the line that passes through the point (−7,−4) with slope 10/7 is y = (10/7)x + 6

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The startup company needs to sell 68 skateboards in order to break even

To solve this problem, we have to find the profit of the company and what is required to break-even from total sales.

C(x) = 10x + 500

r(x) = -x² + 70x

Profit = revenue - cost

profit = (-x² + 70x) - 10x + 500

profit = -x² + 70x - 10x + 500

profit = -x² + 60x + 500

Solving the quadratic equation

x = 67.4 ≅68

For the startup to break even, they need to sell at least 68 skateboard.

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Answer:false

Step-by-step explanation:

Answer:

ez hi

Step-by-step explanation:

ez

The sum of n terms of geometric sequence with n=5, a₁ =4, r=3 is given by = 484.

Given that the sequence is geometric.

First term is = a₁ = 4

Common ratio is = r = 3

The number of terms for which the sum to be determined = n = 5

So the required sum of n terms of given geometric sequence is given by,

S [tex]=a_1\times\frac{r^n-1}{r-1}[/tex]

S [tex]=4\times\frac{3^5-1}{3-1}[/tex]

S = 4*((243-1)/2)

S = (4*242)/2

S = 484

Hence the sum of the given geometric sequence is 484.

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Answer: (-2, -2)

Step-by-step explanation:

Right now, the coordinates of point C are (1, -3).

It is first moved 3 units to the left, so the point C would change to (1 - 3, -3) = (-2, -3)

It is then moved 2 units up, so point C would change to (-2, -3 + 2) = (-2, -1)

Answer:

????? you did not show the net of the prism

Step-by-step explanation:

Answer:

b) it's a polyhedron

I don't know what else to say

Answer:

The answer would be the first one because when you factor -3 out, inside of the parentheses should be all positive because negative times negative is positive.

Answer:

[tex]w=\frac{y+1}{a+2}[/tex]

Step-by-step explanation:

[tex]y-aw=2w-1 \\ \\ y+1=2w+aw \\ \\ y+1=w(a+2) \\ \\ w=\frac{y+1}{a+2}[/tex]

Answer:

[ D ] 140

Step-by-step explanation

4 x 265 = 1060

1060 - 1200 = -140

the answer is 140  i hope this helped <3

To find the set of numbers with a given mean we can assume them as consecutive terms, Zina did the same thing.

Mean or Arithmetic mean is the average of the given set of numbers. It is also denoted as the equal distribution of values for a given data. To calculate the mean of data, we can use the following formula  

Mean/Average = Sum of observations ÷ Number of observations

Here we have

The average of 5 numbers is 85

Let's assume that the 5 numbers are 5 consecutive numbers and the five numbers are x, x+1, x+2, x+3, x+4, and x+5  [ for simple calculations ]  

Average of 5 numbers = Sum of numbers / 5

⇒ 85 = (x+ x+ 1 + x+2 + x+3 + x+4 ) /5

⇒ 425 = 5x + 10  

⇒ 5x = 415

⇒ x = 83

Then the 5 numbers are 83, 84, 85, 86, and 87

Therefore,

To find the set of numbers with a given mean we can assume them as consecutive terms and we can calculate the mean, Zina did the same thing.  

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