Which best describes her prediction?

#24, i am getting <img src="https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D1%260%260%26%5Cfrac%7B18%7D%7B7%7D%20

sveticcg [70]

It looks like you're talking about row-reducing an augmented matrix to solve the system of equations. Your answer is almost correct. The last row should read 0, 0, 1, 2/7.

The given system translates to

$\left[ \begin{array}{ccc|c} 2 & -3 & 1 & 2 \\ 1 & -1 & 2 & 2 \\ 1 & 2 & -3 & 4 \end{array} \right]$

Eliminate x from the last two rows by combining -2 (row 2) and row 1, and -2 (row 3) and row 1; that is,

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

2x - 3y + z - 2x + 2y - 4z = 2 - 4

-y - 3z = -2

and

(2x - 3y + z) - 2 (x + 2y - 3z) = 2 - 2 (4)

2x - 3y + z - 2x - 4y + 6z = 2 - 8

-7y + 7z = -6

In augmented matrix form, this step yields

$\left[ \begin{array}{ccc|c} 2 & -3 & 1 & 2 \\ 0 & -1 & -3 & -2 \\ 0 & -7 & 7 & -6 \end{array} \right]$

I'll omit these details in the remaining steps.

Eliminate y from the last row by combining -7 (row 2) and row 3 :

$\left[ \begin{array}{ccc|c} 2 & -3 & 1 & 2 \\ 0 & -1 & -3 & -2 \\ 0 & 0 & 28 & 8 \end{array} \right]$

Multiply the last row by 1/28 :

$\left[ \begin{array}{ccc|c} 2 & -3 & 1 & 2 \\ 0 & -1 & -3 & -2 \\ 0 & 0 & 1 & 2/7 \end{array} \right]$

Eliminate z from the second row by combining 3 (row 3) and row 2 :

$\left[ \begin{array}{ccc|c} 2 & -3 & 1 & 2 \\ 0 & -1 & 0 & -8/7 \\ 0 & 0 & 1 & 2/7 \end{array} \right]$

Multiply the second row by -1 :

$\left[ \begin{array}{ccc|c} 2 & -3 & 1 & 2 \\ 0 & 1 & 0 & 8/7 \\ 0 & 0 & 1 & 2/7 \end{array} \right]$

Eliminate y and z from the first row by combining 3 (row 2), -1 (row 3), and row 1 :

$\left[ \begin{array}{ccc|c} 2 & 0 & 0 & 36/7 \\ 0 & 1 & 0 & 8/7 \\ 0 & 0 & 1 & 2/7 \end{array} \right]$

Multiply the first row by 1/2 :

$\left[ \begin{array}{ccc|c} 1 & 0 & 0 & 18/7 \\ 0 & 1 & 0 & 8/7 \\ 0 & 0 & 1 & 2/7 \end{array} \right]$

8 0

3 years ago

Which calculation would result in the decimal point moving two spaces to the right in a decimal number?

lora16 [44]

The rule associated with moving decimal places, and multiplying by a value or multiple of 10, would be the following :

If you divide a value by 10 or a multiple of 10, you would move the decimal place to the left number of times as there are zeros in the multiple.

(Assuming that there are no zeros in the numerator value)

If you multiply by 10 multiple, then you would move the decimal to the right that many times as there are 0's in the value.

The solution would be that the decimal number is multiplied by 100.

4 0

3 years ago

Read 2 more answers

Question 8

Ratling [72]

I believe the answer is A

6 0

3 years ago

If a woman takes an early pregnancy test, she will either test positive, meaning that the test says she is pregnant, or test neg

k0ka [10]

Answer:

0.0098

Step-by-step explanation:

Probability of being pregnant:100/1000

=1/10.

98% chance:=98/100 ×1/10

=98/1000

Therefore the probability that she really is pregnant is: 0.098

3 0

3 years ago

Which of the following is equivalent to this expression?

qaws [65]

Answer:

6^8

Step-by-step explanation:

(6^2)^3*6^2

= 6^(2*3)*6^2

= 6^6*6^2

= 6^(6+2)

= 6^8

8 0

3 years ago