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3 years ago

An equation is shown below: 5(2x-8) +15 = -15 write the steps you will use to solve the equation and explain each step

Mathematics

2 answers:

faust18 [17]3 years ago

6 0

Answer:

5(2x-8)+15=-15

10x-40+15=-15

10x-25=-15

+25 +25 (add 25 to both sides)

____________

10x=10

divide by 10 on both sides

x=1

lorasvet [3.4K]3 years ago

4 0

Answer:

x=1

Step-by-step explanation:

First youd distribute the 5 to the 2x-8 so that way you can combine like terms and make the equation smaller

10x - 40 + 15 = -15

combine the -40 and 15

10x - 25 = -15

add 25 to both sides to get 10x by itself on the one side. you have to add 25 to the -15 because the two sides must stay balanced

10x = 10

divide by 10 to get x by itself. you must divide since x is being multiplied by 10

x=1

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Whats the difference of squares

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An example of the difference of squares would be: a^2-b^2 = (a+b)(a-b)

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3 years ago

A particular telephone number is used to receive both voice calls and fax messages. Suppose that 25% of the incoming calls invol

bagirrra123 [75]

Answer:

a) 0.214 = 21.4% probability that at most 4 of the calls involve a fax message

b) 0.118 = 11.8% probability that exactly 4 of the calls involve a fax message

c) 0.904 = 90.4% probability that at least 4 of the calls involve a fax message

d) 0.786 = 78.6% probability that more than 4 of the calls involve a fax message

Step-by-step explanation:

For each call, there are only two possible outcomes. Either it involves a fax message, or it does not. The probability of a call involving a fax message is independent of other calls. So we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

25% of the incoming calls involve fax messages

This means that $p = 0.25$

25 incoming calls.

This means that $n = 25$

a. What is the probability that at most 4 of the calls involve a fax message?

$P(X \leq 4) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4)$ .

In which

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 0) = C_{25,0}.(0.25)^{0}.(0.75)^{25} = 0.001$

$P(X = 1) = C_{25,1}.(0.25)^{1}.(0.75)^{24} = 0.006$

$P(X = 2) = C_{25,2}.(0.25)^{2}.(0.75)^{23} = 0.025$

$P(X = 3) = C_{25,3}.(0.25)^{3}.(0.75)^{22} = 0.064$

$P(X = 4) = C_{25,4}.(0.25)^{4}.(0.75)^{21} = 0.118$

$P(X \leq 4) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) = 0.001 + 0.006 + 0.025 + 0.064 + 0.118 = 0.214$

0.214 = 21.4% probability that at most 4 of the calls involve a fax message

b. What is the probability that exactly 4 of the calls involve a fax message?

$P(X = 4) = C_{25,4}.(0.25)^{4}.(0.75)^{21} = 0.118$

0.118 = 11.8% probability that exactly 4 of the calls involve a fax message.

c. What is the probability that at least 4 of the calls involve a fax message?

Either less than 4 calls involve fax messages, or at least 4 do. The sum of the probabilities of these events is 1. So

$P(X < 4) + P(X \geq 4) = 1$

We want $P(X \geq 4)$ . Then

$P(X \geq 4) = 1 - P(X < 4)$

In which

$P(X < 4) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3)$

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 0) = C_{25,0}.(0.25)^{0}.(0.75)^{25} = 0.001$

$P(X = 1) = C_{25,1}.(0.25)^{1}.(0.75)^{24} = 0.006$

$P(X = 2) = C_{25,2}.(0.25)^{2}.(0.75)^{23} = 0.025$

$P(X = 3) = C_{25,3}.(0.25)^{3}.(0.75)^{22} = 0.064$

$P(X$

$P(X \geq 4) = 1 - P(X < 4) = 1 - 0.096 = 0.904$

0.904 = 90.4% probability that at least 4 of the calls involve a fax message.

d. What is the probability that more than 4 of the calls involve a fax message?

Very similar to c.

$P(X \leq 4) + P(X > 4) = 1$

From a), $P(X \leq 4) = 0.214)$

Then

$P(X > 4) = 1 - 0.214 = 0.786$

0.786 = 78.6% probability that more than 4 of the calls involve a fax message

8 0

3 years ago

Find the inequality represented by the graph

Nuetrik [128]

Answer:

y>=1*x+2

Step-by-step explanation:

y>=k*x+n

we know that 2=k+n and 0=-2k+n

so 4=2k+n and 0=-2k+n

now 4=2n so n=2

now k=1

so y>=1*x+2

7 0

3 years ago

Read 2 more answers

HELP ME PLEASEEEEEEEE ASAPPPP !!

OLEGan [10]

Answer:

C and D

Step-by-step explanation:

Mathematically, a unit circle is one in which the value of the radius is 1 unit

Generally, for a unit circle we have it that;

r^2 = x^2 + y^2

where (x,y) represents the coordinates of a point on the unit circle

But from above, r = 1

Thus:

x^2 + y^2 = 1

Looking at option C, by squaring each coordinate, we have

(6/7)^2 = 36/49 and the second as 13/49

by adding both, we have

36/49 + 13/49 = 49/49 = 1

Thus, we have this as a coordinate on the unit circle

For the last option;

(5/13)^2 = 25/169 and (12/13)^2 = 144/169

Adding both, we have;

25/169 + 144/169 = 169/169 = 1

So this is also a point on the unit circle

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3 years ago

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MakcuM [25]

Answer:

Step-by-step explanation:

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3 years ago