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mars1129 [50]
3 years ago
12

The matrix C=[1,-2_-3,7] was used to encode a phrase to [7,-28,-25,-35,-2_-21,107,90,123,17]. Find C^-1 and use it to decode the

matrix.
Mathematics
1 answer:
posledela3 years ago
6 0
C=  \left[\begin{array}{cc}1&-2\\-3&7\end{array}\right]  \\ C^{-1}= \left[\begin{array}{cc}7&2\\3&1\end{array}\right]  \\ \left[\begin{array}{cc}7&2\\3&1\end{array}\right] \times   \left[\begin{array}{ccccc}7&-28&-25&-35&-2\\-21&107&90&123&17\end{array}\right]  \\ =\left[\begin{array}{ccccc}49-42&-196+214&-175+180&-245+246&-14+34\\21-21&-84+107&-75+90&-105+123&-6+17\end{array}\right] \\ =\left[\begin{array}{ccccc}7&18&5&1&20\\0&23&15&18&11\end{array}\right]
is the required matrix.
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Case cost $3.82 , unit cost $0.32,paper cost ,$0.03, condiment cost $0.02 what is the item total cost?
Luda [366]

Answer:

item total cost: 4.19

5 0
3 years ago
Blake and his brother are participating in their school’s food drive. Blake has collected 6 1/3 pounds of food and his brother h
sergejj [24]

They will need 2 5/12 more pounds to reach their goal.

<h3>Sum and difference of fractions</h3>

Given the following information as shown:

  • Amount Blake collected = 6 1/3 pounds
  • Amount his brother collected = 5 3/4 pounds

If their goal is to collect 14 1/2 pounds of food by the end of the month, the remaining food they need to collect will be expressed as:

y =14 1/2 - (6 1/3 + 5 3/4)

y = 14 1/2 - (19/3  + 23/4)

y = 29/2 - (76+69/12)

y = 29/2 - (145/12)

y = 174-145/12

y = 29/12

y = 2 5/12

Hence they will need 2 5/12 more pounds to reach their goal.

Learn more on sum and difference of fractions here:  brainly.com/question/24205483

5 0
2 years ago
13x=-21-6y and -8x=36+6y
IgorLugansk [536]

Answer:

x=3\\y=-10

Step-by-step explanation:

13x=-21-6y\\-8x=36+6y

Let's take one of the equations and solve for x. I'll take the first one.

13x=-21-6y

Divide by 13.

x=\frac{-21-6y}{13}

Now replace x in the second equation.

-8x=36+6y\\-8(\frac{-21-6y}{13} )=36+6y

Distribute -8

\frac{168+48y}{13}=36+6y

Break down the fraction.

\frac{168}{13}+\frac{48}{13}y=36+6y

Subtract \frac{168}{13}

\frac{48}{13}y=36+6y-\frac{168}{13}

Subtract 6y

\frac{48}{13}y-6y=36-\frac{168}{13}

Combine like terms;

\frac{48-13*6}{13}y=\frac{36*13-168}{13}

Solve;

\frac{48-78}{13}y=\frac{468-168}{13}

Keep solving;

\frac{-30}{13}y=\frac{300}{13}

Multiply by the negative reciprocal of the fraction next to y.

(-\frac{13}{30} )\frac{-30}{13}y=\frac{300}{13}(-\frac{13}{30} )

On the right side; 13 and 13 become 1. 300/30 = 30/3 = 10

y=-10

After having found y, replace it in any of the equations to find x.

13x=-21-6y\\13x=-21-6(-10)\\13x=-21+60\\13x=39\\x=\frac{39}{13}\\ x=3

6 0
3 years ago
Read 2 more answers
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tensa zangetsu [6.8K]

Answer:

His rate in chapters per hour is 8 chapters per hour

Step-by-step explanation:

If you divide 56 by 7 you get 8 also if you want to check to be sure you can just multiply 8 and 7 or 7 and 8

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Answer:

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22.6 + 18.7 = 41.3

41.3 - 2.5 = 38.8

38.8 litres

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2 years ago
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