a) find the value of 2x+y wehn x =4 and y =3 b) find the value of a^2 + b when a = -2 and b = 5

Answer:

A,D and E

Step-by-step explanation:

We are given that a function

[tex]f(x)=49(\frac{1}{7})^x[/tex]

The given function is exponential function .

The exponential function is defined for all real values of x.

Therefore, domain of f=Set of  all real numbers

Substitute x=0

[tex]y=f(0)=49>0[/tex]

Range of f is greater than 0.

x=1

[tex]y(1)=\frac{49}{7}[/tex]

x=2

[tex]y=49(\frac{1}{7})^2=\frac{1}{7}y(1)[/tex]

As x increases by 1, each value of y is one-seventh of the previous y-value.

Therefore, option A,D and E are true.

Answer:

A D E

Step-by-step explanation:

Edge2020 quiz

Answer:

7.5* 10^8

Step-by-step explanation:

(1.5 x 10^5)(5 x 10^3)

Multiply the numbers

1.5*5=7.5

Add the exponents

10 ^(5+3) = 10^8

Put back together

7.5* 10^8

This is in scientific notation

Answer:

The full name of the place is the "Danat Jebel Dhanna".  The Jebel Dhanna is currently located in the Abu Dhabi.  It is said that it is one of the most best beach in the UAE, they also say that it is the biggest resort, of course, with a bunch of hotels.

hope this helps ;)

best regards,

`FL°°F~` (floof)

Answer:

13-n=4

Subtract both sides by 13

-n=-9

n=9

Step-by-step explanation:

13 less means - and a number means n that you don’t know. is means = sign. And so we get the answer that I gave you. Thank you

Answer:

Option C (-4,-1) (In Quadrant III)

Step-by-step explanation:

Coordinate = (-4,1)

=> Reflecting over y-axis will make the coordinate (4,1)

=> Reflecting across x-axis will make the coordinate (4,-1)

=> Rotating 180 will make it (-4,-1)

Answer:

7

Step-by-step explanation:

hh

ht

th

tt

so it's a 1/4 chance

1/4 * 28 = 7

Answer:

7

Step-by-step explanation:

The probability of both coins landing on heads is:

1/2 × 1/2 = 1/4

Multiply by 28.

1/4 × 28

= 7

Answer:

there will be 9 id no. which it contains

Answer:

7 and 12

Step-by-step explanation:

7 and 12 are ok

17 is not

hope this helps

The solution of the inequality x < 17 will be all the real numbers less than 17. Then the correct options are A and B.

Inequality is defined as an equation that does not contain an equal sign. Inequality is a term that describes a statement's relative size and can be used to compare these two claims.

The allocation of weights to the important variables that produce the calculation's optimum is referred to as a direct consequence.

The inequality is given below.

x < 17

The solution of the inequality x < 17 will be all the real numbers less than 17. Then the correct options are A and B.

More about the inequality link is given below.

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Answer:

{-1, -8}

Step-by-step explanation:

Please enclose "1 - 3x" inside parentheses so the reader will know that you want the square root of all of "1 - 3x".

Squaring both sides of the given equation, we get:

1 - 3x = x^2 + 6x + 9, or  x^2 + 6x + 8 + 3x, or

x^2 + 9x + 8 = 0.  Factoring, we get:  (x + 8)(x + 1) = 0, so that the solutions are {-1, -8}.

Answer:

I hope the given equation is :

{-1, -8}

First step to solve this equation to remove square root from the left side. So, take square on each sides of the equation. Therefore,

1 - 3x = (x + 3)²

1 - 3x = (x + 3)*(x + 3) Since a² = a * a

1 - 3x = x² + 3x + 3x + 3² By multiplication.

1 - 3x = x² + 6x + 9 Combine the like terms.

x² + 6x + 9 - 1 + 3x = 0 Subtract 1 and add 3x from each sides of equation

x² + 9x + 8 = 0 Combine the like terms.

Next step is to factor the trinomial to solve the above equation for x.

For that break downn the constant 8 into two multiples so that the addition of the multiples will result the coefficient of x = 9.

So, 8 = 1 * 8

Addition of 1 and 8 will give 9. So, next step is to replace 9x with 1x + 8x. So,

x² + 1x + 8x + 8 = 0

(x² + 1x) + (8x + 8) = 0 Group the terms.

x ( x + 1) + 8 (x + 1 ) = 0 Take out the common factor from each group.

(x +1 ) ( x + 8 ) = 0 Take out the common factor (x + 1).

So, x + 1 = 0 and x + 8 = 0 Set up each factor equal to 0.

Hence, x = -1 and - 8.

Next step is to plug in -1 and -8 in the original equation to cross check the solutions.

For x = -1,

Simplify each sides separately.

2 = 2

2 = 2 is correct. So, x = -1 satisfy the equation.

Hence, x = -1 is the real solution of the given equation.

Similarly let's plug in x = -8 now. So,

Simplify each sides separately.

5 = 2

5 = 2 is not true. So, x = -8 is the extraneous solution.

Therefore, the only solution is x = -1.

Hence, the correct choice is C.

Hope this helps you!

Step-by-step explanation:

mark brainlies plssssssssss

Answer:8.2 x 10^5

Step-by-step explanation:

Answer:

it’s C

Step-by-step explanation:

No, the vertices of the image and pre-image do not correspond

No, the vertices of the image and pre-image do not correspond, Micaela tried to rotate the square 180° about the origin. Hence, option C is correct.

A figure can be rotated by 90 degrees clockwise by rotating each vertex of the figure 90 degrees clockwise about the origin.

Let's take the vertices of a square with points at (+1,+1), (-1,+1), (-1,-1), and (+1,-1), centered at the origin, can be found in the following positions after rotation:

Micaela's rotation must be accurate if it led to the same points. Her rotation is incorrect if the points are different, though.

It is impossible to tell if Micaela's rotation is accurate without more details or a diagram.

Thus, option C is correct.

For more information about rotation about the origin, click here:

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Answer:

X is 3 units.

Step-by-step explanation:

Volume of prism is cross sectional area multiplied by length. So 1/2 ×2× x ×2 into 3x, which is equal to 6x^2. So, 6x^2=54. Therefore, x=3.

Answer:

[tex]z=\frac{404-409}{\frac{24}{\sqrt{42}}}=-1.35[/tex]  

The p value for this case is given by:

[tex]p_v =P(z<-1.35)=0.0885[/tex]  

For this case the p value is higher than the significance level given so we have enough evidence to FAIL to reject the null hypothesis and we can't conclude that the true mean is significantly less than 409

Step-by-step explanation:

Information given

[tex]\bar X=404[/tex] represent the sample mean

[tex]\sigma=24[/tex] represent the population standard deviation

[tex]n=42[/tex] sample size  

[tex]\mu_o =409[/tex] represent the value to verify

[tex]\alpha=0.01[/tex] represent the significance level for the hypothesis test.  

z would represent the statistic (variable of interest)  

[tex]p_v[/tex] represent the p value

Hypothesis to test

We want to verify if the true mean is less than 409, the system of hypothesis would be:  

Null hypothesis:[tex]\mu \geq 409[/tex]  

Alternative hypothesis:[tex]\mu < 409[/tex]  

The statistic for this case is given by:

[tex]z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}[/tex] (1)  

Replacing the info we got:

[tex]z=\frac{404-409}{\frac{24}{\sqrt{42}}}=-1.35[/tex]  

The p value for this case is given by:

[tex]p_v =P(z<-1.35)=0.0885[/tex]  

For this case the p value is higher than the significance level given so we have enough evidence to FAIL to reject the null hypothesis and we can't conclude that the true mean is significantly less than 409

Work Shown:

log(200) = log(2^3*5^2)

log(200) = log(2^3) + log(5^2)

log(200) = 3*log(2) + 2*log(5)

log(200) = 3*q + 2*p

log(200) = 2p + 3q

The log rules I used were

log(A*B) = log(A)+log(B)

log(A^B) = B*log(A)

The equivalent expression of log(200) is 2p + 3q

The logarithmic expression is given as:

[tex]\mathbf{log 200}[/tex]

Rewrite as:

[tex]\mathbf{log(200) = log (25 \times 8)}[/tex]

Express as exponents

[tex]\mathbf{log(200) = log (5^2 \times 2^3)}[/tex]

Split

[tex]\mathbf{log(200) = log (5^2) +log(2^3)}[/tex]

Apply law of logarithms

[tex]\mathbf{log(200) = 2log (5) +3log(2)}[/tex]

From the question;

log(5) = p and log(2) = q

So, we have:

[tex]\mathbf{log(200) = 2p +3q}[/tex]

Hence, the equivalent expression of log(200) is 2p + 3q

Read more about logarithmic expressions at:

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Answer:

Store A

Step-by-step explanation:

So. What we are going to want to do here is start off by having two stores obviously. And we have the sales that they have. If the discount is 20% rhat means the new price will be 80% of 250. So we take 250 x .8 = 200

If the discount is 25%, that means the new price will be 75% of what it was before hand. So we take 280 x .75 = 210. So the better price is at Store a

Answer:

A. The E(Y) is 0.80

B. The expected amount of the surcharges is $165

Step-by-step explanation:

A. In order to calculate the E(Y), we would have to calculate the following formula:

E(Y)=∑yp(y)

E(Y)=(0*0.5)+(1*0.25)+(2*0.20)+(3*0.05)

E(Y)=0+0.25+0.40+0.15

E(Y)=0.80

B. In order to calculate the expected amount of the surcharges we would have to calculate the following formula:

E($110Y∧2)=110E(Y∧2)

=110∑y∧2p(y)

=110((0∧2*0.5)+(1∧2*0.25)+(2∧2*0.20)+(3∧2*0.05))

110(0+0.25+0.80+0.45)

=$165

Answer:

[tex] \frac{1}{2} [/tex]

Step-by-step explanation:

[tex]scale \: factor = \frac{5}{10} = \frac{1}{2} \\ [/tex]

Answer:

[tex]\boxed{\sf \ \ \ 49a^8b^6c^2 \ \ \ }[/tex]

Step-by-step explanation:

Hello,

[tex](-7a^4b^3c)^2=(-1)^27^2a^{4*2}b^{3*2}c^2=49a^8b^6c^2[/tex]

as

[tex](-1)^2=1[/tex]

Answer:

a) P(x > 43) = 0.9599

b) P(x < 42) = 0.0228

c) P(x > 57.5) = 0.03

d) P(x = 42) = 0.

e) P(x<40 or x>55) = 0.1118

f) 43.42

g) Between 46.64 and 53.36.

h) Above 45.852.

Step-by-step explanation:

When the distribution is normal, we use the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this question, we have that:

[tex]\mu = 50, \sigma = 4[/tex]

a) x>43

This is 1 subtracted by the pvalue of Z when X = 43. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{43 - 50}{4}[/tex]

[tex]Z = -1.75[/tex]

[tex]Z = -1.75[/tex] has a pvalue of 0.0401

1 - 0.0401 = 0.9599

P(x > 43) = 0.9599

b) x<42

This is the pvalue of Z when X = 42.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{42 - 50}{4}[/tex]

[tex]Z = -2[/tex]

[tex]Z = -2[/tex] has a pvalue of 0.0228

P(x < 42) = 0.0228

c) x>57.5

This is 1 subtracted by the pvalue of Z when X = 57.5. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{57.5 - 50}{4}[/tex]

[tex]Z = 1.88[/tex]

[tex]Z = 1.88[/tex] has a pvalue of 0.97

1 - 0.97 = 0.03

P(x > 57.5) = 0.03

d) P(x = 42)

In the normal distribution, the probability of an exact value is 0. So

P(x = 42) = 0.

e) x<40 or x>55

x < 40 is the pvalue of Z when X = 40. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{40 - 50}{4}[/tex]

[tex]Z = -2.5[/tex]

[tex]Z = -2.5[/tex] has a pvalue of 0.0062

x > 55 is 1 subtracted by the pvalue of Z when X = 55. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{55 - 50}{4}[/tex]

[tex]Z = 1.25[/tex]

[tex]Z = 1.25[/tex] has a pvalue of 0.8944

1 - 0.8944 = 0.1056

0.0062 + 0.1056 = 0.1118

P(x<40 or x>55) = 0.1118

f) 5% of the values are less than what X value?

X is the 5th percentile, which is X when Z has a pvalue of 0.05, so X when Z = -1.645.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]-1.645 = \frac{X - 50}{4}[/tex]

[tex]X - 50 = -1.645*4[/tex]

[tex]X = 43.42[/tex]

43.42 is the answer.

g) 60% of the values are between what two X values (symmetrically distributed around the mean)?

Between the 50 - (60/2) = 20th percentile and the 50 + (60/2) = 80th percentile.

20th percentile:

X when Z has a pvalue of 0.2. So X when Z = -0.84.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]-0.84 = \frac{X - 50}{4}[/tex]

[tex]X - 50 = -0.84*4[/tex]

[tex]X = 46.64[/tex]

80th percentile:

X when Z has a pvalue of 0.8. So X when Z = 0.84.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]0.84 = \frac{X - 50}{4}[/tex]

[tex]X - 50 = 0.84*4[/tex]

[tex]X = 53.36[/tex]

Between 46.64 and 53.36.

h) 85% of the values will be above what X value?

Above the 100 - 85 = 15th percentile, which is X when Z has a pvalue of 0.15. So X when Z = -1.037.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]-1.037 = \frac{X - 50}{4}[/tex]

[tex]X - 50 = -1.037*4[/tex]

[tex]X = 45.852[/tex]

Above 45.852.

Answer:

[tex]x=2$\pm$\sqrt{42}[/tex]

Step-by-step explanation:

The given equation is:

[tex]x^{2} -4x-9=29\\\Rightarrow x^{2} -4x-9-29=0\\\Rightarrow x^{2} -4x-38=0[/tex]

Formula:

A quadratic equation [tex]ax^{2} +bx+c=0[/tex] has the following roots:

[tex]x=\dfrac{-b+\sqrt D}{2a}\ and\\x=\dfrac{-b-\sqrt D}{2a}[/tex]

Where [tex]D= b^{2} -4ac[/tex]

Comparing the equation with [tex]ax^{2} +bx+c=0[/tex]

a = 1

b = -4

c= -38

Calculating D,

[tex]D= (-4)^{2} -4(1)(-38)\\\Rightarrow D = 16+152 = 168[/tex]

Now, finding the roots:

[tex]x=\dfrac{-(-4)+\sqrt {168}}{2\times 1}\\\Rightarrow x=\dfrac{4+2\sqrt {42}}{2}\\\Rightarrow x=2+\sqrt {42}\\and\\x=\dfrac{-(-4)-\sqrt {168}}{2\times 1}\\\Rightarrow x=\dfrac{4-2\sqrt {42}}{2}\\\Rightarrow x=2-\sqrt {42}[/tex]

So, the solution is:

[tex]x=2$\pm$\sqrt{42}[/tex]

Answer is A or the first one

Answer:

The answer is "[tex]\bold{\frac{32}{3}}\\[/tex]"

Step-by-step explanation:

The rectangle should also be symmetrical to it because of the symmetry to the y-axis  The pole of the y-axis.  Its lower two vertices are (-x,0). it means that  

and (-x,0), and (x,0). Therefore the base measurement of the rectangle is 2x. The top vertices on the parabola are as follows:  

The calculation of the height of the rectangle also is clearly 16-x^2, (-x,16,-x^2) and (x,16,-x^2).  

The area of the rectangle:

[tex]A(x)=(2x)(16-x^2)\\\\A(x)=32x-2x^3[/tex]

The local extremes of this function are where the first derivative is 0:

[tex]A'(x)=32-6x^2\\\\32-6x^2=0\\\\x= \pm\sqrt{\frac{32}{6}}\\\\x= \pm\frac{4\sqrt{3}}{3}\\\\[/tex]

Simply ignore the negative root because we need a positive length calculation

It wants a maximum, this we want to see if the second derivative's profit at the end is negative.

[tex]A''\frac{4\sqrt{3}}{3} = -12\frac{4\sqrt{3}}{3}<0\\\\2.\frac{4\sqrt{3}}{3}= \frac{8\sqrt{3}}{3}\\\\\vertical \ dimension\\\\16-(\frac{4\sqrt{3}}{3})^2= \frac{32}{3}[/tex]

Question:

You are interested in estimating the the mean age of the citizens living in your community. In order to do this, you plan on constructing a confidence interval; however, you are not sure how many citizens should be included in the sample. If you want your sample estimate to be within 5 years of the actual mean with a confidence level of 97% , how many citizens should be included in your sample? Assume that the standard deviation of the ages of all the citizens in this community is 18 years.

Answer:

61.03

Step-by-step explanation:

Given:

Standard deviation = 18

Sample estimate = 5

Confidence level = 97%

Required:

Find sample size, n.

First find the Z value. Using zscore table

Z-value at a confidence level of 97% = 2.17

To find the sample size, use the formula below:

[tex] n = (Z * \frac{\sigma}{E})^2[/tex]

[tex] n = ( 2.17 * \frac{18}{5})^2 [/tex]

[tex] n = (2.17 * 3.6)^2 [/tex]

[tex] n = (7.812)^2 [/tex]

[tex] n = 61.03 [/tex]

Sample size = 61.03

Answer:145

Step-by-step explanation: $19=20 76=80 53=50 23=20 12=10 total = 180 325-180 =145

Answer:

5.12 x 10¹¹ bit

Step-by-step explanation:

1GB = 8 x 10⁹ bits

so 64gb = 64 x 8 x 10⁹

= 512 x 10⁹

= 5.12 x 10¹¹ bits

scientific notation = 5.12 x 10¹¹ bits

standard Notation = 512 ,000,000,000 bits.

Answer:

  7

Step-by-step explanation:

The number of cells in a tile is 4. If colored alternately, there are 3 of one color and 1 of the alternate color. To balance the coloring, an even number of tiles is needed. Hence the board dimensions must be multiples of 4.

In the given range, there are 7 such boards:

  4×4, 8×8, 12×12, 16×16, 20×20, 24×24, and 28×28

Answer:

Step-by-step explanation:

Given that;

the following procedure for accomplishing our task are:

1. Flip the coin.

2. Flip the coin again.

From here will know that the coin is first flipped twice

3. If both flips land on heads or both land on tails, it implies that we return to step 1 to start again. this makes the flip to be insignificant since both flips land on heads or both land on tails

But if the outcomes of the two flip are different i.e they did not land on both heads or both did not land on tails , then we will consider such an outcome.

Let the probability of head = p

so P(head) = p

the probability of tail be = (1 - p)

This kind of probability follows a conditional distribution and the probability  of getting heads is :

[tex]P( \{Tails, Heads\})|\{Tails, Heads,( Heads ,Tails)\})[/tex]

[tex]= \dfrac{P( \{Tails, Heads\}) \cap \{Tails, Heads,( Heads ,Tails)\})}{ {P( \{Tails, Heads,( Heads ,Tails)\}}}[/tex]

[tex]= \dfrac{P( \{Tails, Heads\}) }{ {P( \{Tails, Heads,( Heads ,Tails)\}}}[/tex]

[tex]= \dfrac{P( \{Tails, Heads\}) } { {P( Tails, Heads) +P( Heads ,Tails)}}[/tex]

[tex]=\dfrac{(1-p)*p}{(1-p)*p+p*(1-p)}[/tex]

[tex]=\dfrac{(1-p)*p}{2(1-p)*p}[/tex]

[tex]=\dfrac{1}{2}[/tex]

Thus; the probability of getting heads is [tex]\dfrac{1}{2}[/tex] which typically implies that the coin is fair

(b) Could we use a simpler procedure that continues to flip the coin until the last two flips are different and then lets the result be the outcome of the final flip?

For a fair coin (0<p<1) , it's certain that both heads and tails at the end of the flip.

The procedure that is talked about in (b) illustrates that the procedure gives head if and only if the first flip comes out tail with probability 1 - p.

Likewise , the procedure gives tail if and and only if the first flip comes out head with probability of  p.

In essence, NO, procedure (b) does not give a fair coin flip outcome.

Answer:

B) 92.03 < μ < 97.97

99% confidence interval for the mean score of all students.

92.03 < μ < 97.97

Step-by-step explanation:

Step(i):-

Given sample mean (x⁻) = 95

standard deviation of the sample (s) = 6.6

Random sample size 'n' = 30

99% confidence interval for the mean score of all students.

[tex]((x^{-} - Z_{0.01} \frac{S}{\sqrt{n} } , (x^{-} + Z_{0.01} \frac{S}{\sqrt{n} })[/tex]

step(ii):-

Degrees of freedom

ν =   n-1 = 30-1 =29

[tex]t_{0.01} = 2.462[/tex]

99% confidence interval for the mean score of all students.

[tex]((95 - 2.462 \frac{6.6}{\sqrt{30} } , 95 + 2.462\frac{6.6}{\sqrt{30} } )[/tex]

( 95 - 2.966 , 95 + 2.966)

(92.03 , 97.97)

Final answer:-

99% confidence interval for the mean score of all students.

92.03 < μ < 97.97

Answer:

-3

Step-by-step explanation:

every sequence goes down by -3

Answer:

take away 3. the common difference is 3

Step-by-step explanation:

take away 3

Answer:

[tex]solution \\ 3(5x) + 8(2x) \\ = 3 \times 5x + 8 \times 2x \\ = 15x + 16x \\ = 31x[/tex]

hope this helps...

Good luck on your assignment...

The expression  [tex]3(5x) + 8(2x)[/tex] in simplest form is 31x.

To simplify the expression [tex]3(5x) + 8(2x)[/tex], we can apply the distributive property:

[tex]3(5x) + 8(2x)[/tex]

[tex]= 15x + 16x[/tex]

Combining like terms, we have:

[tex]15x + 16x = 31x[/tex]

Therefore, the expression [tex]3(5x) + 8(2x)[/tex] simplifies to [tex]31x.[/tex]

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Answer:

Step-by-step explanation:

The question is in complete. Here is the complete question.

"The dimensions of a triangular pyramid are shown below. The height of

the pyramid is 6 inches. What is the volume in cubic inches?

Base of triangle = 1in

height of triangle = 5in"

Given the dimension of the triangular base of base 1 inch and height 5inches with the height of the pyramid to be 6inches, the volume of the triangular pyramid is expressed as [tex]V = \frac{1}{3}BH[/tex] where;\

B = Base area

H = Height of the pyramid

Base area  B = area of the triangular base = [tex]\frac{1}{2}bh[/tex]

b = base of the triangle

h = height of the triangle

B = [tex]\frac{1}{2} * 5 * 1\\[/tex]

[tex]B = 2.5in^{2}[/tex]

Since H = 6inches

Volume of the triangular pyramid = [tex]\frac{1}{3} * 2.5 * 6\\[/tex]

[tex]V = 2.5*2\\V =5in^{3}[/tex]