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3 years ago

Solve the system of equation by elimination.

Mathematics

1 answer:

Nataly_w [17]3 years ago

7 0

Answer:

[1]XXXX9x−9y=27

[2]XXXX7y−3x=−11

Resequence the terms of [2] so the variables occur in the same order as in [1]

[3]XXXX−3x+7y=−11

Multiply [3] by 3

[4]XXXX−9x+21y=−33

Add [1] and [4]

[5]XXXX12y=−6

Divide [5] by12

[6]XXXXy=−12

Substitute y=−12 into [1]

[7]XXXX9x−9(−12)=27

Simplifying

[8]XXXX9x=452

[9]XXXXx=52

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Write the linear equation for this table.

Vedmedyk [2.9K]

Answer:

its A

Step-by-step explanation:

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3 years ago

At a local University, it is reported that 81% of students own a wireless device. If 5 students are selected at random, what is

Sphinxa [80]

Answer:

34.87% probability that all 5 have a wireless device

Step-by-step explanation:

For each student, there are only two possible outcomes. Either they own a wireless device, or they do not. The probability of a student owning a wireless device is independent from other students. 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.

81% of students own a wireless device.

This means that $p = 0.81$

If 5 students are selected at random, what is the probability that all 5 have a wireless device?

This is P(X = 5) when n = 5. So

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

$P(X = 5) = C_{5,5}.(0.81)^{5}.(0.19)^{0} = 0.3487$

34.87% probability that all 5 have a wireless device

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3 years ago

How many edges does a rectanglar prism have?

natta225 [31]

It has 12 edges in total

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3 years ago

On Ursula’s birthday, her cousins hid her presents in a secret location and gave her this cryptogram to identify the location: 9

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Answer:

it is in the attic

Step-by-step explanation:

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3 years ago

Can u guys pls help me with this homework

gladu [14]

The value of √(7 * 23 - 1)/8 is 4.47, the values of a, b and c are -14/11, -10/11 and 3, respectively and the area of the shape is 5√5 + 5 square meters

<h3>How to evaluate the radical expression?</h3>

The question goes thus:

If √5 = 2.236, evaluate √(7 * 23 - 1)/8

We have:

√(7 * 23 - 1)/8

Evaluate the product of 7 and 23

√(7 * 23 - 1)/8 = √(161 - 1)/8

Evaluate the difference of 161 and 1

√(7 * 23 - 1)/8 = √160/8

Evaluate the quotient of 160 and 8

√(7 * 23 - 1)/8 = √20

Express 20 as the product 4 and 5

√(7 * 23 - 1)/8 = √(4 * 5)

Expand the product

√(7 * 23 - 1)/8 = √4 * √5

Express √4 as 2

√(7 * 23 - 1)/8 = 2 * √5

Substitute √5 = 2.236

√(7 * 23 - 1)/8 = 2 * 2.236

Evaluate the product

√(7 * 23 - 1)/8 = 4.472

Approximate

√(7 * 23 - 1)/8 = 4.47

Hence, the value of √(7 * 23 - 1)/8 is 4.47

<h3>How to simplify the radical expression?</h3>

The expression is given as:

(3√2 + 5√6)/(3√2 - 5√6)

Rationalize the above expression

(3√2 + 5√6)/(3√2 - 5√6) * (3√2 + 5√6)/(3√2 + 5√6)

Evaluate the product

(3√2 + 5√6)²/((3√2)² - (5√6)²)

Simplify the denominator

(3√2 + 5√6)²/(18 - 150)

This gives

[(3√2)² + (5√6)² + 2 *(3√2) * (5√6)]/(-132)

Simplify the numerator

[168 + 120√3]/(-132)

Simplify the fraction

-14/11 - 10√3/11

Hence, the values of a, b and c are -14/11, -10/11 and 3, respectively

<h3>How to determine the area?</h3>

The area is calculated as:

A = 1/2 * (Sum of parallel bases) * Height

So, we have:

A = 1/2 * (4 + 3√5 + 6 - √5) * √5

Evaluate the like terms

A = 1/2 * (10 + 2√5) * √5

Evaluate the product

A = (5 + √5) * √5

Evaluate the product

A = 5√5 + 5

Hence, the area of the shape is 5√5 + 5 square meters

Read more about rational expressions at:

brainly.com/question/8008240

#SPJ1

6 0

2 years ago