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BlackZzzverrR [31]
2 years ago
12

NEED ANSWER ASAP!!

Mathematics
1 answer:
erik [133]2 years ago
7 0

Answer:

A=-2; B=-1

Step-by-step explanation:

3a - 2b + 4 =0

2a -5b -1 = 0

Let's multiple the top equation by 2, and the bottom by -3, and then use addition.

[3a - 2b + 4 =0]*2

[2a -5b -1 = 0]*(-3)

6a-4b+8=0

-6a+15b+3=0

Now add the two equations together:

11b + 11 = 0

Subtract 11 from both sides

11b = -11

Divide both sides by 11

b=-1

Substitute in the first equation:

3a - 2(-1) + 4 = 0

Simplify to get 3a+6 = 0

Subtract 6 from both sides to get 3a = -6

Divide both sides by 3 to get a=-2

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B and C are correct, A and D are incorrect

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The probability that two people have the same birthday in a room of 20 people is about 41.1%. It turns out that
salantis [7]

Answer:

a) Let X the random variable of interest, on this case we know that:

X \sim Binom(n=20, p=0.411)

This random variable represent that two people have the same birthday in just one classroom

b) We can find first the probability that one or more pairs of people share a birthday in ONE class. And we can do this:

P(X\geq 1 ) = 1-P(X

And we can find the individual probability:

P(X=0) = (20C0) (0.411)^0 (1-0.411)^{20-0}=0.0000253

And then:

P(X\geq 1 ) = 1-P(X

And since we want the probability in the 3 classes we can assume independence and we got:

P= 0.99997^3 = 0.9992

So then the probability that one or more pairs of people share a birthday in your three classes is approximately 0.9992

Step-by-step explanation:

Previous concepts

A Bernoulli trial is "a random experiment with exactly two possible outcomes, "success" and "failure", in which the probability of success is the same every time the experiment is conducted". And this experiment is a particular case of the binomial experiment.

The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".

The probability mass function for the Binomial distribution is given as:  

P(X)=(nCx)(p)^x (1-p)^{n-x}  

Where (nCx) means combinatory and it's given by this formula:  

nCx=\frac{n!}{(n-x)! x!}  

Solution to the problem

Part a

Let X the random variable of interest, on this case we know that:

X \sim Binom(n=20, p=0.411)

This random variable represent that two people have the same birthday in just one classroom

Part b

We can find first the probability that one or more pairs of people share a birthday in ONE class. And we can do this:

P(X\geq 1 ) = 1-P(X

And we can find the individual probability:

P(X=0) = (20C0) (0.411)^0 (1-0.411)^{20-0}=0.0000253

And then:

P(X\geq 1 ) = 1-P(X

And since we want the probability in the 3 classes we can assume independence and we got:

P= 0.99997^3 = 0.9992

So then the probability that one or more pairs of people share a birthday in your three classes is approximately 0.9992

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3 years ago
Identify the parent function that can be used to graph the function f(x)=-9(x+5)^2
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Answer:

Option a) f(x)=x^2

Step-by-step explanation:

The parent function that can be used to graph the function f(x)=-9(x+5)^2 is f(x)=x^2

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How do I do this? I don’t understand
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You have to input the 5 into the x place. so it would be y=3(5) and you get the answer y=15
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The glacier moves 5 centimeters in 8 days. How many days does it take the glacier to move 1 centimeter?
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