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4 years ago

How do i solve this?

Mathematics

1 answer:

n200080 [17]4 years ago

5 0

The polynomial is not factorable, so use the quadratic formula.

y^2 + 8y + 19 = 0

x = (-b +- sqrt(b^2 - 4ac))/(2a)

x = (-8 +- sqrt(8^2 - 4(1)(19))/(2 * 1)

x = (-8 +- sqrt(64 - 76))/2

x = (-8 +- sqrt(-12))/2

If you have not learned imaginary/complex numbers, then the answer is "No solution" since there is no real number solution.

If you have learned imaginary/complex numbers, then we'll continue.

x = (-8 +- 2i sqrt(3))/2

x = -4 +- i sqrt(3)

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-9(-5k+3m) +9m-5(-5m+9k)

liraira [26]

Answer:

the ansmwer is * grabs a notebook and doodle the equation* hmm.. it is 7m

happy to help!!!

3 0

3 years ago

A multiple-choice test contains 10 questions. There are four possible answers for each question. a) In how many ways can a stude

AnnZ [28]

Answer :

<h3> $4^{10}$ <u> =1048576 ways </u> a student can answer the questions on the test if the student answers every question.</h3>

Step-by-step explanation:

Given that a multiple-choice test contains 10 questions and there are 4 possible answers for each question.

∴ Answers=4 options for each question.

<h3>To find how many ways a student can answer the given questions on the test if the student answers every question :</h3>

Solving this by product rule

Product rule :

<u>If one event can occur in m ways and a second event occur in n ways, the number of ways of two events can occur in sequence is then m.n</u>

From the given the event of choosing the answer of each question having 4 options is given by

The 1st event of picking the answer of the 1st question=4 ,

2nd event of picking the answer of the 2nd question=4 ,

3rd event of picking the answer of the 3rd question=4

,....,

10th event of picking the answer of the 10th question=4.

It can be written as by using the product rule

$=4.4.4.4.4.4.4.4.4.4$

$=4^{10}$

$=1048576$

<h3>∴ there are 1048576 ways a student can answer the questions on the test if the student answers every question.</h3>

3 0

3 years ago

Find the coefficient of variation for each of the two sets of data, then compare the variation. Round results to one decimal pla

svp [43]

Here is the correct computation of the question given.

Find the coefficient of variation for each of the two sets of data, then compare the variation. Round results to one decimal place. Listed below are the systolic blood pressures (in mm Hg) for a sample of men aged 20-29 and for a sample of men aged 60-69.

Men aged 20-29: 117 122 129 118 131 123

Men aged 60-69: 130 153 141 125 164 139

Group of answer choices

Men aged 20-29: 4.8%

Men aged 60-69: 10.6%

There is substantially more variation in blood pressures of the men aged 60-69.

Men aged 20-29: 4.4%

Men aged 60-69: 8.3%

There is substantially more variation in blood pressures of the men aged 60-69.

Men aged 20-29: 4.6%

Men aged 60-69: 10.2 %

There is substantially more variation in blood pressures of the men aged 60-69.

Men aged 20-29: 7.6%

Men aged 60-69: 4.7%

There is more variation in blood pressures of the men aged 20-29.

Answer:

(c)

Men aged 20-29: 4.6%

Men aged 60-69: 10.2 %

There is substantially more variation in blood pressures of the men aged 60-69.

Step-by-step explanation:

From the given question:

The coefficient of variation can be determined by the relation:

$coefficient \ of \ variation = \dfrac{standard \ deviation}{mean}*100$

We will need to determine the coefficient of variation both men age 20 - 29 and men age 60 -69

To start with;

The coefficient of men age 20 -29

Let's first find the mean and standard deviation before we can do that ;

SO .

Mean = $\dfrac{\sum \limits^{n}_{i-1}x_i}{n}$

Mean = $\frac{117+122+129+118+131+123}{6}$

Mean = $\dfrac{740}{6}$

Mean = 123.33

Standard deviation $= \sqrt{\dfrac{\sum (x_i- \bar x)^2}{(n-1)} }$

Standard deviation = $\sqrt{\dfrac{(117-123.33)^2+(122-123.33)^2+...+(123-123.33)^2}{(6-1)} }$

Standard deviation = $\sqrt{\dfrac{161.3334}{5}}$

Standard deviation = $\sqrt{32.2667}$

Standard deviation = 5.68

The $coefficient \ of \ variation = \dfrac{standard \ deviation}{mean}*100$

$coefficient \ of \ variation = \dfrac{5.68}{123.33}*100$

Coefficient of variation = 4.6% for men age 20 -29

For men age 60-69 now;

Mean = $\dfrac{\sum \limits^{n}_{i-1}x_i}{n}$

Mean = $\frac{ 130 + 153 + 141 + 125 + 164 + 139}{6}$

Mean = $\dfrac{852}{6}$

Mean = 142

Standard deviation $= \sqrt{\dfrac{\sum (x_i- \bar x)^2}{(n-1)} }$

Standard deviation = $\sqrt{\dfrac{(130-142)^2+(153-142)^2+...+(139-142)^2}{(6-1)} }$

Standard deviation = $\sqrt{\dfrac{1048}{5}}$

Standard deviation = $\sqrt{209.6}$

Standard deviation = 14.48

The $coefficient \ of \ variation = \dfrac{standard \ deviation}{mean}*100$

$coefficient \ of \ variation = \dfrac{14.48}{142}*100$

Coefficient of variation = 10.2% for men age 60 - 69

Thus; Option C is correct.

Men aged 20-29: 4.6%

Men aged 60-69: 10.2 %

There is substantially more variation in blood pressures of the men aged 60-69.

4 0

3 years ago

Given the geometric sequence where a1 = 3 and r = √2 find a9

Zigmanuir [339]

Answer:

$a_9=48$

Step-by-step explanation:

we are given

sequence is geometric

so, we can use nth term formula

$a_n=a_1(r)^{n-1}$

we have

$a_1=3$

$r=\sqrt{2}$

we have to find a9

so, we can plug n=9

we get

$a_9=3(\sqrt{2})^{9-1}$

$a_9=2^4\cdot \:3$

$a_9=48$

8 0

3 years ago

Express 25km/h into m/s?

Helen [10]

Answer:

3600(seconds) can also be expressed as 1(kilometer/hour) = 5/18 (meters/second), which is its simplified form. To convert km/h to m/s, directly multiply the given value of speed by the fraction 5/18.

Step-by-step explanation:

I think that explanation is obvious

7 0

2 years ago