What numbers are always prime numbers?

25 — 3x = 40 x = Please answer quick thanks

Keith_Richards [23]

Answer:

x=-5

Step-by-step explanation:

-3x+25=40. You want to isolate x so you have to subtract 25 from both sides. -3x=15. We then want x to be isolated so we have to divide both sides by -3 to make x by itself. x=-5. Therefore, x=-5.

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4 0

2 years ago

Read 2 more answers

第 5 个问题 a multiple choice exam has 10 questions. each question has 3 possible answers, of which one is correct. a student knows

tatuchka [14]

The chances that the student was merely guessing is 1/3.

Bayes Theorem determines the conditional probability of an event A given that event B has already occurred.

denoted by

$P(A/B)=\frac{P(A)*P(B/A)}{P(B)}$

let A be the event that the student knows the answer .

B be the event that the student does not knows the answer .

and

E be the event he gets answer correct .

According to the given question

$P(A)=\frac{4}{10} \\\\ P(B)=1-\frac{4}{10} =\frac{6}{10}$

Probability that the answer is correct ,given that he knows the answer is

$P(E/A)=1$

Probability that the answer is correct ,given that he guesses it is

$P(E/B)=\frac{1}{3}$ [as the MCQ has 3 options and only one is correct]

We need to find the probability that he guesses the answer given that it is correct.

Required probability $P(B/E)=\frac{P(B)*P(E/B)}{P(A)*P(E/A)+P(B)*P(E/B)}$

Substituting the values we get

$P(B/E)=\frac{\frac{6}{10} *\frac{1}{3} }{\frac{4}{10} *1+\frac{6}{10} *\frac{1}{3} }$

$=\frac{6}{30}*\frac{30}{18} \\ \\ =\frac{6}{18} \\ \\ =\frac{1}{3}$

Therefore , the chances that the student was merely guessing is 1/3.

Learn more about Probability here brainly.com/question/13140147

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8 0

8 months ago

5. Select ALL of the following expressions that are linear functions (they do not need to be in slope-intercept form).

Anon25 [30]

Answer:

The following are the LINEAR functions.

$2x\:+\:4\:=\:3x\:-\:8$

$y = 3x - 2$

$1$

$3x\:+\:-y\:=\:24$

Step-by-step explanation:

We know that linear functions are the equations with a straight line graph in an XY plane.

Also, a linear function is a function of the form

$f(x)=mx+b$

where m is the slope and b is the y-intercept. The only power of the variable is 1.

So, from the given expressions we can determine that:

1) $y^2=\:5x\:+2$

$y^2=\:5x\:+2$ is NOT a linear function because the power of y is 2, hence the graph won't be a straight line. Therefore, it is not a linear function

2) $2x\:+\:4\:=\:3x\:-\:8$

$2x\:+\:4\:=\:3x\:-\:8$

$x=12$

This is a linear equation is an equation of a straight line, written in one variable. The only power of the variable is 1

3) $y = 3x - 2$

$y = 3x - 2$ is a linear function because it is of the form $f(x)=mx+b$ and the power of its x and y variables is 1. Hence, the function has a straight line graph.

4) $y\:+\:x^2\:=\:12$

$y\:+\:x^2\:=\:12$ is NOT a linear function because the power of x is 2, hence the graph won't be a straight line. Therefore, it is not a linear function.

5) $y\:=\:x^2\:+\:2x$

$y\:=\:x^2\:+\:2x$ is NOT a linear function because the power of x is 2, hence the graph won't be a straight line. Therefore, it is not a linear function.

6) $1$

$1$ is a constant function and a constant function is also considered linear in this context, as it is a polynomial of degree $0$ or is the $0$ polynomial.

7) $3x\:+\:-y\:=\:24$

$3x\:+\:-y\:=\:24$ is a linear function as the power of its x and y variables is 1. Hence, the function has a straight line graph. Therefore, it is a linear function.

In a summary, the following are the LINEAR functions.

$2x\:+\:4\:=\:3x\:-\:8$

$y = 3x - 2$

$1$

$3x\:+\:-y\:=\:24$

7 0

2 years ago

The Arthur Company manufactures kitchen utensils. The company is currently producing well below its full capacity. The Benton Co

icang [17]

Answer:

The increase in Arthur's operating profits would be $1120.

Step-by-step explanation:

Given:

The Arthur Company manufactures kitchen utensils. The company is currently producing well below its full capacity. The Benton Company has approached Arthur with an offer to buy 16,000 utensils at $0.70 each. Arthur sells its utensils wholesale for $0.80 each; the average cost per unit is $0.78, of which $0.15 is fixed costs.

If Arthur were to accept Benton's offer.

Now, to find the increase in Arthur's operating profits.

The average cost per unit = $0.78.

The fixed costs = $0.15.

So, to get the variable cost we subtract the fixed cost from the average cost per unit:

$0.78-0.15=0.63.$