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3 years ago

Multiply the following complex numbers:

Mathematics

1 answer:

professor190 [17]3 years ago

4 0

Answer:

63+22i

Step-by-step explanation:

(8 - 3i)(6 + 5i)

FOIL

first: 8*6 = 48

outer: 8*5i = 40i

inner: -3i* 6 = -18i

last: -3i*5i = -15 i^2 = -15(-1) = 15

Add together

48+40i -18i +15

Combine like terms

63+22i

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3. A piece of white oak has a densityof 0.77 g/cm and a mass of 100 g,what would be the volume of thesample? PLEASE HELP!

Nezavi [6.7K]

$\text{Volume}=129.87cm^3$

Explanation

Step 1

the density of an object is given by:

$\text{density}=\text{ }\frac{mass}{\text{volume}}$

Step 2

let

$\begin{gathered} \text{density}=0.77\frac{g}{cm^3} \\ \text{mass}=\text{ 100 g} \\ \end{gathered}$

Step 3

replace,

$\begin{gathered} \text{density}=\text{ }\frac{mass}{\text{volume}} \\ 0.77\frac{g}{cm^3}=\frac{100g}{\text{volume}} \\ \text{volume}\cdot0.77\frac{g}{cm^3}=\text{1}00\text{ g} \\ \\ \text{Volume}=\frac{100\text{ g}}{0.77\frac{g}{cm^3}} \\ \text{Volume}=129.87cm^3 \end{gathered}$

I hope this helps you

5 0

1 year ago

The calibration of a scale is to be checked by weighing a 13 kg test specimen 25 times. Suppose that the results of different we

Natali5045456 [20]

Solution :

a).

Given : Number of times, n = 25

Sigma, σ = 0.200 kg

Weight, μ = 13 kg

Therefore the hypothesis should be tested are :

$H_0 : \mu = 13$

$H_a : \mu \neq 13$

b). When the value of $\overline x = 12.84$

Test statics :

$Z=\frac{(\overline x - \mu)}{\frac{\sigma}{\sqrt n}}$

$Z=\frac{(14.82-13)}{\frac{0.2}{\sqrt {25}}}$

$=\frac{1.82}{0.04}$

= 45.5

P-value = 2 x P(Z > 45.5)

= 2 x 1 -P (Z < 45.5) = 0

Reject the null hypothesis if P value < α = 0.01 level of significance.

So reject the null hypothesis.

Therefore, we conclude that the true mean measured weight differs from 13 kg.

3 0

3 years ago

Question 1: An online music store is offering a promotion. When you spend $30 or more, you receive 3 songs for free. You buy an

ch4aika [34]

Answer:

10 + m ≥ 30

You must spend AT MOST $20 or more

Step-by-step explanation:

Basically you have already spent 10 dollars and you have to pay MORE than or equal to 30. You cannot pay less than because you want the free songs. So the sign has to be ≥ or the inequality will not be true.

10 + m ≥ 30

10 - 10 + m ≥ 30 - 10 ( subtract 10 from each side to isolate m)

m ≥ 20 ( we are left with this )

The answer is :

m ≥ 20

You must spend at most 20 dollars more to get the 3 free cd's. Your welcome :D

5 0

4 years ago

2. Which of the following is a linear inequality in two variables?

tester [92]

A !! 7x-4y=3 is linear !!

Please mark BRAINLEST

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3 years ago

A color printer prints 24 pages in 9 minutes. How many minutes does it take per page?

Gnom [1K]

Answer:

it gets almost 3 pages but it gets 2 pages per minute

Step-by-step explanation:

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3 years ago