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3 years ago

Elimination using multiplication What is the best answer? 2x+y=0

Mathematics

2 answers:

Ksenya-84 [330]3 years ago

5 0

Answer:

x = -2, y = 4

Step-by-step explanation:

2x + y = 0

5x + 3y = 2

Multiply the top equation by -3 so that one variable can be eliminated:

-3(2x + y = 0)

5x + 3y = 2

Simplify the top equation:

-6x - 3y = 0

5x + 3y = 2

Add the equations:

-x = 2

Solve for x:

x = -2

Substitute x back into one of the equations:

5(-2) + 3y = 2

Solve for y:

-10 + 3y = 2

3y = 12

y = 4

JulijaS [17]3 years ago

3 0

Answer:

x=-2, y=4. (-2, 4).

Step-by-step explanation:

2x+y=0

5x+3y=2

----------------

-3(2x+y)=-3(0)

5x+3y=2

-------------------

-6x-3y=0

5x+3y=2

---------------

-x=2

x=-2

2(-2)+y=0

-4+y=0

y=0-(-4)

y=0+4

y=4

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Determine whether the sequence converges or diverges. If it converges, find the limit. (If an answer does not exist, enter DNE.)

In-s [12.5K]

Answer:

The sequence diverges.

Step-by-step explanation:

A sequence $a_{n}$ converges when $\lim_{n \rightarrow \infty} a_{n}$ is a real number.

In this question, the sequence given is:

$a_{n} = 4n\cos{(7n\pi)}$

The cosine is always going to be between -1 and 1, so for the convergence of the sequence, we look it as: $a_{n} = 4n$ . So

$\lim_{n \rightarrow \infty} a_{n} = \lim_{n \rightarrow \infty} 4n = \infty$

Since the limit is not a real number, the sequence diverges.

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3 years ago

I need help 1. 2. 3.

Reptile [31]

1. North America, Africa, Asia, Europe

2. South America, Antarctica, and Australia

3. North America, South America and Antarctica.

4 0

3 years ago

Mike and Beth both write the decimal 0.8 (0.88888...)as a fraction. Mike: 45 Beth: 89 Which student wrote the correct fraction?

fenix001 [56]

Answer:

see the explanation

Step-by-step explanation:

we have

0.888...

This is a repeating decimal (Is a decimal that has a digit, or a block of digits, that repeat over and over and over again without ever ending)

Convert to fraction number

Let

x=0.888...

10x=8.888...

Subtract 0.888... from 8.888... to remove the decimal

10x-x=8.888...-0.888...

9x=8

Solve for x

x=8/9

therefore

Mike fraction is incorrect

because 4/5=0.8

0.8 is a terminating decimal (It's a decimal with a finite number of digits)

Mike's mistake was considering the number as a terminating decimal instead of a repeating decimal

Beth is correct

because

If you divide 8/9

the result is 0.8888888...

3 0

3 years ago

Bryan and Jadyn had barbeque potato chips and soda at a football party. Bryan ate 5 oz of chips and drank 1 cup of soda for a

MaRussiya [10]

Answer:

1 oz of chips has 120mg of sodium, while in 1 cup of soda there are 50mg of sodium.

Step-by-step explanation:

This question can be solved by a system of equations.

I am going to say that:

x is the number of mg of sodium in 1 oz of chips.

y is the number of mg of sodium in a cup of soda.

Bryan ate 5 oz of chips and drank 1 cup of soda for a total of 650 mg of sodium.

This means that:

$5x + y = 650$

Jadyn ate 1 oz of chips and drank 5 cups of soda for a total of 250 mg of sodium.

This means that:

$x + 5y = 250$

From the first equation:

$y = 650 - 5x$

Replacing in the second

$x + 5(650 - 5x) = 250$

$x + 3250 - 25x = 250$

$25x = 3000$

$x = \frac{3000}{25}$

$x = 120$

$y = 650 - 5x = 650 - 5*120 = 650 - 600 = 50$

1 oz of chips has 120mg of sodium, while in 1 cup of soda there are 50mg of sodium.

5 0

3 years ago

A professor went to a website for rating professors and looked up the quality rating and also the "easiness" of the six full-tim

Marat540 [252]

We are asked to determine the correlation factor "r" of the given table. To do that we will first label the column for "Quality" as "x" and the column for "Easiness" as "y". Like this:

Now, we create another column with the product of "x" and "y". Like this:

Now, we will add another column with the squares of the values of "x". Like this:

Now, we add another column with the squares of the values of "y":

Now, we sum the values on each of the columns:

Now, to get the correlation factor we use the following formula:

$r=\frac{n\Sigma xy-\Sigma x\Sigma y}{\sqrt{(n\Sigma x^2-(\Sigma x)^2)(n\Sigma y^2-(\Sigma y)^2)}}$

Where:

$\begin{gathered} \Sigma xy=\text{ sum of the column of xy} \\ \Sigma x=\text{ sum of the column x} \\ \Sigma y=\text{ sum of the column y} \\ \Sigma x^2=\text{ sum of the column x\textasciicircum2} \\ \Sigma y^2=\text{ sum of the column y\textasciicircum2} \\ n=\text{ number of rows} \end{gathered}$

Now we substitute the values, we get:

$r=\frac{\left(6)(70.56)-(25.2)(16.4\right)}{\sqrt{((6)(107.12)-(25.2)^2)((6)(47.82)-(16.4)^2)}}$

Solving the operations:

$r=0.858$

Therefore, the correlation factor is 0.858. If the correlation factor approaches the values of +1, this means that there is a strong linear correlation between the variables "x" and "y" and this correlation tends to be with a positive slope.

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1 year ago