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Oksana_A [137]
3 years ago
12

Dina encoded a secret phrase using matrix multiplication. She multiplied the clear text code for each letter by the matrix (See

image) to get a matrix that represents the encoded text. By which matrix does Dina multiply the encoded text to get the matrix for the clear text code?

Mathematics
2 answers:
serg [7]3 years ago
7 0

Answer:

C= 1   1

    3  2

Step-by-step explanation:

belka [17]3 years ago
6 0

Dina needs to multiply by the inverse of C. The inverse of a 2×2 matrix is easily calculated from its definition: the transpose of the cofactor matrix divided by the determinant. Here, that is

C^{-1}=\left[\begin{array}{cc}-1&-1\\-3&-2\end{array}\right] \cdot\dfrac{1}{(-2)(-1)-(3)(1)} =\left[\begin{array}{cc}1&1\\3&2\end{array}\right]


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Alonso plans to buy a new kayak that costs $2100. The sales tax in his county is 7%. What is the amount of sales tax he will pay
Arisa [49]

Answer:

D $147.00

Step-by-step explanation:

$2100.00×7%

8 0
2 years ago
Please help!!!!! <br> Which defines the piecewise function shown?
denis-greek [22]
<h2>Hello!</h2>

The answer is:

The second piecewise function,

f(x)=\left \{ {{-x-2,x

<h2>Why?</h2>

To answer the question, we need to find which piecewise function contains the graphs shown in the picture, we have that first line shown, is decreasing and exists from the negative numbers to 0,  and the line cuts the x-axis and the y-axis at "-2", for the second line shown,  we have that is decreasing but exists from 0 (including it) to the the positive numbers.

So, finding which piecewise satisfies the function shown, we have:

- First piecewise function:

f(x)=\left \{ {{-x-2,x

First line,

We have the first line,

-x-2

The variable has a negative coefficient (-1), meaning that the function (line) is decreasing, also we can see that the function does exists from all the numbers less than 0, to 0, and it cuts the x-axis at -2 and the y-axis at -2.

Second line,

\frac{x}{2}\geq 0

The variable has positive coefficient, meaning that the function (line) is increasing.

Hence, since the second line is not decreasing, the piecewise function is not the piecewise function shown in the picture.

- Second piecewise function,

f(x)=\left \{ {{-x-2,x

First line,

We have the first line,

-x-2

The variable has a negative coefficient (-1), meaning that the function (line) is decreasing, also we can see that the function does exist from all the numbers less than 0, to 0.

Second line,

-\frac{x}{2}\geq 0

The variable has a negative coefficient ((-\frac{1}{2}), meaning the the unction (line) is decreasing, also we can see that the function does exists from 0 (including it) to the positive numbers.

Hence, we have that the correct option is the second piecewise function,

f(x)=\left \{ {{-x-2,x

Note: I have attached a picture for better understanding.

Have a nice day!

3 0
3 years ago
Read 2 more answers
What is −30−6r= -36 ?
Nadya [2.5K]

-30-6r=36

We move all terms to the left:

-30-6r-(36)=0

We add all the numbers together, and all the variables

-6r-66=0

We move all terms containing r to the left, all other terms to the right

-6r=66

r=66/-6

r=-11

7 0
3 years ago
Read 2 more answers
What number two numbers when multiplied equal 24 but when added equal -4
madam [21]
Since it says when Added they are a negative and when multiplied they are positive, we know our two numbers are negative.
think of all multiples of 24
6 and 4
8 and 3
12 and 2
24 and 1
however, none of our choices here would be correct. 
5 0
3 years ago
For which inequality is {x | x R, x &gt; 6} the solution set?
CaHeK987 [17]

Answer:

C

Step-by-step explanation:

<em>B: 2X + 12 > 3</em>

2x > -9

x> -9/2

<em>C: 2X - 5 > 7</em>

2x > 12

x > 6

<em>D: 2x - 6 > 24</em>

2x > 30

x > 15

Hope this helps ^-^

6 0
2 years ago
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