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3 years ago

Please help)Simplify: (r – 7)(r + 7)

Mathematics

2 answers:

PtichkaEL [24]3 years ago

5 0

Answer:

Im pretty sure the answer is

C) r^2 - 49

Step-by-step explanation:

Serggg [28]3 years ago

4 0

Answer:

r^2-49

Step-by-step explanation:

r^2+7r-7r-49 || r^2-49

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At Munder Difflin Paper Company, the manager Mitchell Short randomly places golden sheets of paper inside of 30% of their paper

Korvikt [17]

Answer:

90.67% probability that John finds less than 7 golden sheets of paper

Step-by-step explanation:

For each container, there are only two possible outcomes. Either it contains a golden sheet of paper, or it does not. The probability of a container containing a golden sheet of paper is independent of other containers. 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.

At Munder Difflin Paper Company, the manager Mitchell Short randomly places golden sheets of paper inside of 30% of their paper containers.

This means that $p = 0.3$

14 of these containers of paper.

This means that $n = 14$

What is the probability that John finds less than 7 golden sheets of paper?

$P(X < 7) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5) + P(X = 6)$

In which

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

$P(X = 0) = C_{14,0}.(0.3)^{0}.(0.7)^{14} = 0.0068$

$P(X = 1) = C_{14,1}.(0.3)^{1}.(0.7)^{13} = 0.0407$

$P(X = 2) = C_{14,2}.(0.3)^{2}.(0.7)^{12} = 0.1134$

$P(X = 3) = C_{14,3}.(0.3)^{3}.(0.7)^{11} = 0.1943$

$P(X = 4) = C_{14,4}.(0.3)^{4}.(0.7)^{10} = 0.2290$

$P(X = 5) = C_{14,5}.(0.3)^{5}.(0.7)^{9} = 0.1963$

$P(X = 6) = C_{14,6}.(0.3)^{6}.(0.7)^{8} = 0.1262$

$P(X < 7) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5) + P(X = 6) = 0.0068 + 0.0407 + 0.1134 + 0.1943 + 0.2290 + 0.1963 + 0.1262 = 0.9067$

90.67% probability that John finds less than 7 golden sheets of paper

7 0

3 years ago

Solve the inequality for x: -5x - 49 > 113

Valentin [98]

-5x - 49 > 113
Add 49 to both sides
-5x > 162
Divide both sides by -5
x > -32.4
Hope this helps!

8 0

3 years ago

Read 2 more answers

The pythagorean theorem equation

nikklg [1K]

A^2+b^2=c^2
Is the Pythagorean theorem

6 0

3 years ago

Read 2 more answers

If cos(x)=1/4 what is sin(x) and tan(x)

anygoal [31]

You can use the identity
cos(x)² +sin(x)² = 1
to find sin(x) from cos(x) or vice versa.

(1/4)² +sin(x)² = 1
sin(x)² = 1 - 1/16
sin(x) = ±(√15)/4

Then the tangent can be computed as the ratio of sine to cosine.
tan(x) = sin(x)/cos(x) = (±(√15)/4)/(1/4)
tan(x) = ±√15

There are two possible answers.
In the first quadrant:
sin(x) = (√15)/4
tan(x) = √15

In the fourth quadrant:
sin(x) = -(√15)/4
tan(x) = -√15

3 0

3 years ago

Can someone please help me with this problem?<br><br> <img src="https://tex.z-dn.net/?f=%20%5Cfrac%7B%28%20x%5E%7B2%7D%20%2B8x%2

hodyreva [135]

First, factor the expression on the top. What two numbers add to get 8 and multiply to 15? 5 and 3! so the top expression factors to (x+3)(x+5). You can cancel the x+3 from the denominator and end up with x+5. Make sense?

7 0

3 years ago