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2 years ago

10

Simplify the expression to a + bi form: (-6 - 9i)(-11 + 7i)

2 answers:

jek_recluse [69]2 years ago

4 0

Answer:

129+57i

Step-by-step explanation:

kumpel [21]2 years ago

3 0

$( - 6 - 9i)( - 11 + 7i) \\ = 66 - 42i + 99i - 63 {i}^{2} \\ = 66 + 57i + 63 \\ = 129 + 57i$

I hope I helped you^_^

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Write the slope intercept form of the equation. <br> Y=Mx+b<br><br> PLEASE SHOW WORK

Debora [2.8K]

Answer:

See below (I hope this helps!)

Step-by-step explanation:

We need to write this in the form y = mx + b.

x + 3y = -12

3y = -x - 12

$y = \frac{1}{3}x - 4$

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3 years ago

What the value of r that makes the value true? r+(-0.14)=0.47

Anika [276]

Answer:

0.61

Step-by-step explanation:

Add 0.14 to both sides of this equation, obtaining r = 0.61.

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3 years ago

To win a trivia game, Nathan must score at least 75 points. Each correct answer is worth 2 1/2 points , and each incorrect answe

Dmitrij [34]

Answer:

He scored $79\frac{1}{2}$ points.

Step-by-step explanation:

Given:

Number of points for a correct answer = $2\frac{1}{2}$

Number of points scored for an incorrect answer = $-\frac{1}{4}$

Therefore, for 35 correct answers, points scored = $35\times 2\frac{1}{2}=35\times \frac{5}{2}=\frac{175}{2}$

Now, for 32 incorrect answers, points scored = $32\times -\frac{1}{4}=-\frac{32}{4}=-8$

Therefore, net number of points scored by Nathan is:

$\frac{175}{2}-8=\frac{175}{2}-\frac{16}{2}=\frac{175-16}{2}=\frac{159}{2}=79\frac{1}{2}$

Therefore, Nathan scored $79\frac{1}{2}$ points.

3 0

3 years ago

Two shooters, Rodney and Philip, practice at a shooting range. They fire rounds each at separate targets. The targets are mark

Sedaia [141]

Complete Question

Answer:

a

$SE = 0.66}$

b

$-3.29 < \mu_1 - \mu_2 < -0.70$

Step-by-step explanation:

From the question we are told that

The sample size is n = 60

The first sample mean is $\= x _1 = 8$

The second sample mean is $\= x _2 = 10$

The first variance is $v_1 = 0.25$

The first variance is $v_2 = 0.55$

Given that the confidence level is 95% then the level of significance is 5% = 0.05

Generally from the normal distribution table the critical value of $\frac{\alpha }{2}$ is

$Z_{\frac{\alpha }{2} } = 1.96$

Generally the first standard deviation is

$\sigma_1 = \sqrt{v_1}$

=> $\sigma_1 = \sqrt{0.25}$

=> $\sigma_1 = 0.5$

Generally the second standard deviation is

$\sigma_2 = \sqrt{v_2}$

=> $\sigma_2 = \sqrt{0.55}$

=> $\sigma_2 = 0.742$

Generally the first standard error is

$SE_1 = \frac{\sigma_1}{\sqrt{n} }$

$SE_1 = \frac{0.5}{\sqrt{60} }$

$SE_1 = 0.06$

Generally the second standard error is

$SE_2 = \frac{\sigma_2}{\sqrt{n} }$

$SE_2 = \frac{0.742}{\sqrt{60} }$

$SE_2 = 0.09$

Generally the standard error of the difference between their mean scores is mathematically represented as

$SE = \sqrt{SE_1^2 + SE_2^2 }$

=> $SE = \sqrt{0.06^2 +0.09^2 }$

=> $SE = 0.66}$

Generally 95% confidence interval is mathematically represented as

$(\= x_1 -\= x_2) -(Z_{\frac{\alpha }{2} } * SE) < \mu_1 - \mu_2 < (\= x_1 -\= x_2) +(Z_{\frac{\alpha }{2} } * SE)$

=> $(8 -10) -(1.96 * 0.66) < \mu_1 - \mu_2 < (8-10) +(Z_{\frac{\alpha }{2} } * 0.66)$

=> $-3.29 < \mu_1 - \mu_2 < -0.70$

5 0

3 years ago

Find the Value of X. Thanks for helping

ser-zykov [4K]

Answer:

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Step-by-step explanation:

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3 years ago

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