All categories

2 years ago

Simplify: (5 + i)(5 − i) A) −12 B) 24i C) 26 D) 8i

Mathematics

2 answers:

Fofino [41]2 years ago

5 0

Answer:

C) 26

Simplify using the FOIL method--used to multiply binomials--and then combine real and imaginary parts of the problem.

5 × 5 = 25 + positive 1(i) = 26

Alik [6]2 years ago

4 0

Answer:

option c, 26

Step-by-step explanation:

(5 + i)(5 - i)

Apply complex arithmetic rule: (a + bi)(a - bi) = a^2 + b^2

a = 5, b =1

(5)^2 + (1)^2

(5)^2 = 25

(1)^2 = 1

25 + 1

You might be interested in

In art class, Arthur has created a triangle painting 1/5 of his painting is purple. He decided he wants to Paint 4/8 of the purp

babymother [125]

$\frac{1}{10}$ part of the whole painting is gold colored.

Solution:

Given that , In art class, Arthur has created a triangle painting $\frac{1}{5}$ of his painting is purple.

He decided he wants to Paint $\frac{4}{8}$ of the purple area gold

We have to find what fraction of the whole painting will be painting?

Now, $\frac{1}{5}$ part of whole painting is purple

And, $\frac{4}{8}$ part of the purple area is gold ⇒ $\frac{4}{8}$ part of the $\frac{1}{5}$ part of whole painting is gold

$\text { Then, fraction of gold color }=\frac{4}{8} \times \frac{1}{5}=\frac{1}{2} \times \frac{1}{5}=\frac{1}{10}$

Hence, $\frac{1}{10}$ part of the whole painting is gold colored.

4 0

3 years ago

Suppose that in a normal half hour of practice, a tennis player expends 280 calories of energy.

sertanlavr [38]

Answer:

308 Calories

Step-by-step explanation:

So we start off with 280 as usual, but I will focus on the percent. The given percent is 110% "effort". What we would need to do here is, Firstly, change the percent into a decimal, and this is done by moving the decimal spot of 110%. What I mean is that 110.% and you move that little period over 2 times to the left and also remove the percent as for now because we will not need it. After that you would get 1.10. This is what we will multiply by. So if we did 280x1.10 it equals 308, and that is how I got 308

Hope this helps!

4 0

3 years ago

Area Compound Shapes Answer Key for Worksheet

Lerok [7]

Answer:

I dont now cause it depends on what you teacher asks of you

3 0

3 years ago

Read 2 more answers

A small business owner estimates his mean daily profit as $970 with a standard deviation of $129. His shop is open 102 days a ye

Katena32 [7]

Answer:

The probability that the shopkeeper's annual profit will not exceed $100,000 is 0.2090.

Step-by-step explanation:

According to the Central Limit Theorem if we have a population with mean μ and standard deviation σ and we select appropriately huge random samples (n ≥ 30) from the population with replacement, then the distribution of the sum of values of X, i.e ∑X, will be approximately normally distributed.

Then, the mean of the distribution of the sum of values of X is given by,

$\mu_{x}=n\mu$

And the standard deviation of the distribution of the sum of values of X is given by,

$\sigma_{x}=\sqrt{n}\sigma$

The information provided is:

μ = $970

σ = $129

n = 102

Since the sample size is quite large, i.e. n = 102 > 30, the Central Limit Theorem can be used to approximate the distribution of the shopkeeper's annual profit.

Then,

$\sum X\sim N(\mu_{x}=98940,\ \sigma_{x}=1302.84)$

Compute the probability that the shopkeeper's annual profit will not exceed $100,000 as follows:

$P (\sum X \leq 100,000) =P(\frac{\sum X-\mu_{x}}{\sigma_{x}}$

$=P(Z$

*Use a z-table for the probability.

Thus, the probability that the shopkeeper's annual profit will not exceed $100,000 is 0.2090.

6 0

3 years ago

Help after this I only have 5 points

Lena [83]

We break all the bracket out :

-0.75 + 2/5 + 0.4 - 3/4

2/5 = 0.4
-3/4 = -0.75
So, we have : -0.75 + 0.4 + 0.4 - 0.75
= (-0.75 - 0.75) + (0.4 + 0.4) = -1.5 + 0.8 = -0.7

3 0

2 years ago