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3 years ago

What is the number system

2 answers:

8 0

A number system is a system for representing numbers of a certain type. We usually use the base 10 number system, or the decimal number system, employing 10 as the base and and requiring 10 different numerals, the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9.

xxTIMURxx [149]3 years ago

6 0

A numeral system (or system of numeration) is a writing system for expressing numbers; that is, a mathematical notation for representing numbers of a given set, using digits or other symbols in a consistent manner. Hope this helps :))

You might be interested in

Let $a$ and $b$ be nonzero real numbers such that

algol [13]

<h3>Answer: -7/2</h3>

=========================================================

Explanation:

Let's expand out (2 - 7i)(a + bi) using the FOIL rule

(2 - 7i)(a + bi) = 2a + 2bi - 7ai - 7bi^2

(2 - 7i)(a + bi) = 2a + 2bi - 7ai - 7b(-1)

(2 - 7i)(a + bi) = 2a + 2bi - 7ai + 7b

(2 - 7i)(a + bi) = (2a+7b) + (2bi-7ai)

(2 - 7i)(a + bi) = (2a+7b) + (2b-7a)i

We're told the result is purely imaginary. What this means is that the real part (2a+7b) is zero, while the imaginary part (2b-7a) is nonzero. If both are zero, then we have 0+0i = 0 which is purely real.

For example, the complex numbers 0-7i and 0+2i are purely imaginary.

Let's use the fact that 2a+7b must be zero to do the following steps:

2a+7b = 0

2a = -7b

a = -7b/2

a/b = -7/2 which is the final answer

We must check to see if 2b-7a is nonzero

2b - 7a = 2b - 7(-7b/2)

2b - 7a = 2b + 24.5b

2b - 7a = 26.5b

The result is nonzero if and only if b is nonzero. Luckily we're told b is nonzero at the top of the problem. So we don't have any worries that (2b-7a) is zero.

Therefore, (2a+7b) + (2b-7a)i will be purely imaginary with a/b = -7/2

------------------

A concrete example:

Let a = -14 and b = 4

a/b = -14/4 = -7/2

(2-7i)(a+bi) = (2-7i)(-14+4i) = 0 + 106i which is purely imaginary.

I'll let you do the steps in expanding that out using the FOIL rule.

4 0

1 year ago

Will give brainliest please help -5x+4-x-1

Serjik [45]

Answer:

− 6 x + 3

Step-by-step explanation:

hope that helps :)

3 0

2 years ago

In the United States, there are 59 different species of mammals that are endangered,

jolli1 [7]

Given Information:

Number of endangered mammal species = 59

Number of endangered bird species = 75

Number of endangered fish species = 68

Required Information:

Probability of either a mammal or a fish = ?

Answer:

P(mammal or fish) = 127/202 = 0.6287 = 62.87%

Step-by-step explanation:

We want to randomly select one animal and find out the probability of either a mammal or a fish.

The total number of endangered species of animals is given by

Total animals = mammal species + bird species + fish species

Total animals = 59 + 75 + 68 = 202

The probability of selecting a endangered mammal is

P(mammal) = no. of endangered mammal/total no. of endangered animals

P(mammal) = 59/202

The probability of selecting a endangered fish is

P(fish) = no. of endangered fish/total no. of endangered animals

P(fish) = 68/202

Finally, the probability of selecting either a mammal or a fish is

P(mammal or fish) = 59/202 + 68/202

P(mammal or fish) = 127/202

P(mammal or fish) = 0.6287

P(mammal or fish) = 62.87%

8 0

3 years ago

Use technology or a z-score table to answer the question.

Alik [6]

Answer:

The second choice: Approximately $65.2\%$ of the pretzel bags here will contain between 225 and 245 pretzels.

Step-by-step explanation:

This explanation uses a z-score table where each $z$ entry has two decimal places.

Let $\mu$ represent the mean of a normal distribution of variable $X$ . Let $\sigma$ be the standard deviation of the distribution. The z-score for the observation $x$ would be:

$\displaystyle z = \frac{x - \mu}{\sigma}$ .

In this question,

$\mu = 240$ .
$\sigma = 9.3$ .

Calculate the z-score for $x_1 = 225$ and $x_2 = 245$ . Keep in mind that each entry in the z-score table here has two decimal places. Hence, round the results below so that each contains at least two decimal places.

$\begin{aligned} z_1 &= \frac{x_1 - \mu}{\sigma} \\ &= \frac{225 - 240}{9.3} \approx -1.61\end{aligned}$ .

$\begin{aligned} z_2 &= \frac{x_2 - \mu}{\sigma} \\ &= \frac{245 - 240}{9.3} \approx 0.54\end{aligned}$ .

The question is asking for the probability $P(225 \le X \le 245)$ (where $X$ is between two values.) In this case, that's the same as $P(-1.61 \le Z \le 0.54)$ .

Keep in mind that the probabilities on many z-table correspond to probability of $P(Z \le z)$ (where $Z$ is no greater than one value.) Therefore, apply the identity $P(z_1 \le Z \le z_2) = P(Z \le z_2) - P(Z \le z_1)$ to rewrite $P(-1.61 \le Z \le 0.54)$ as the difference between two probabilities:

$P(-1.61 \le Z \le 0.54) = P(Z \le 0.54) - P(Z \le -1.61)$ .

Look up the z-table for $P(Z \le 0.54)$ and $P(Z \le -1.61)$ :

$P(Z \le 0.54)\approx 0.70540$ .
$P(Z \le -1.61) \approx 0.05370$ .

$\begin{aligned}& P(225 \le X \le 245) \\ &= P\left(\frac{225 - 240}{9.3} \le Z \le \frac{245 - 240}{9.3}\right)\\&\approx P(-1.61 \le Z \le 0.54) \\ &= P(Z \le 0.54) - P(Z \le -1.61)\\ &\approx 0.70540 - 0.05370 \\& \approx 0.65.2 \\ &= 65.2\% \end{aligned}$ .

3 0

3 years ago

The figure below shows circle with center O and two perpendicular diameters

dlinn [17]

Answer:

Triangles OAB,BOC,COD,DOA are isocele and right , are thus equals and have the same hypothenus . The quadrilater ABCD is a diamond (having 4 sides equals) and its diagonals perpendicular is thus a square.

Step-by-step explanation:

3 0

3 years ago