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3 years ago

Can you think of any 2x2 matrices d for which cd = dc for all 2x2 matrices c? give 2 different examples of such matricesd.

1 answer:

6 0

For any arbitrary 2x2 matrices $\mathbf C$ and $\mathbf D$ , only one choice of $\mathbf D$ exists to satisfy $\mathbf{CD}=\mathbf{DC}$ , which is the identity matrix.

There is no other matrix that would work unless we place some more restrictions on $\mathbf C$ . One such restriction would be to ensure that $\mathbf C$ is not singular, or its determinant is non-zero. Then this matrix has an inverse, and taking $\mathbf D=\mathbf C^{-1}$ we'd get equality.

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Me podrían ayudar y explicarme el proceso please

kakasveta [241]

Answer: Encontrarás las respuestas debajo de cada explicación. Espero que consideres darme brainliest y 5 estrellas, y más importante, que hayas entendido.

Step-by-step explanation:

Esto es la regla de 3. Conoces 3 valores y necesitas encontrar un 4to valor.

Ya sabemos que 1 caja pesa 20kg,

1 - 20kg

ahora queremos saber cuantas cajas (x) equivalen a 7653kg

x - 7653kg

Hacemos un pequeño cuadro poniendo en un lado los numeros de cajas y del otro el peso.

Pongamos la cantidad de cajas en la izquierda y el peso en la derecha

$\frac{1}{x} =\frac{20kg}{7653kg}$

Procedemos a multiplicar en cruz. Solo podemos multiplicar si tenemos ambos valores. En este caso, los valores en cruz que tenemos son 1 y 7653kg porque en la otra cruz (20 y x) tenemos nuestra incognita. Y, por ultimo, dividimos entre el numero cuya cruz es con la incognita (20kg)

Esto nos deja la expresión así;

$x=\frac{1*7653kg}{20kg}$

$x=382.65$

Como una caja no puede ser un numero decimal, redondeamos.

$x=383$

Por lo tanto, se necesitan aproximadamente 383 cajas para que su peso equivalga a 7653 kg.

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La otra pregunta dice: Si una caja pesa 20kg, (1 - 20kg), ¿Cuántas cajas se necesitan para equivaler 9500kg? (x - 9500kg)

Hacemos lo mismo que arriba, ponemos la cantidad de cajas de un lado, y el peso de otro lado.

$\frac{1}{x}=\frac{20kg}{9500kg}$

Multiplicamos aquellos valores en cruz que conozcamos y dividimos por el valor cuya cruz sea con x.

$x=\frac{1*9500kg}{20kg}$

$x=475$

Esta es la cantidad de cajas que se necesitan para que su pesa equivalga a 9500kg.

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Por último, la pregunta dice, ¿Cuántos kilogramos hay en 873 cajas?

Ya sabemos que una caja pesa 20kg ( 1 - 20kg ) y ahora buscamos cuantos kg hay en 873 cajas; es decir, (873 - x)

Nos quedaría así;

$\frac{1}{873}=\frac{20kg}{x}$

Ahora, nuestra cruz es 873 y 20kg, y el divisor es 1.

$x=\frac{873*20kg}{1}$

$x=17460kg$

Este sería el peso de 873 cajas.

5 0

3 years ago

Systems with three variables. please help

kirza4 [7]

X= 6
Y= 0
Z= -2

CHECK
3x + y -2z =22
3(6) + 0 -2(-2) =22
18 + 0 +4= 22
22=22

x+5y+z =4
6 +5(0)+ -2 =4
6 + 0 +-2 = 4
4=4

x+3z=0
6 + 3(-2) =0
6 -6 = 0
0=0

3 0

3 years ago

Tobias has 12 coins in his pocket. Of these coins, 8 were made in the year 2000,and

Free_Kalibri [48]

Answer on attached file.
Bye.

7 0

4 years ago

Im even worse at this

stira [4]

The first sentence is irrelevant information, you can ignore that!

There are 20 players. Each player paid the <em>same amount. </em>

In total, they payed $500,000.

We need x, the amount a single player pays. x times 20 will give us 500,000. This gives us the equation 20x=500,000

Divide both sides by 20 to isolate the variable.

x=25,000

3 0

3 years ago

Read 2 more answers

Please help!!! i need to show work too!!!

Verizon [17]

Answer:

1. 7/10, 2. 25, 3. 1/4 4. 4. 3/5, 5. A

Step-by-step explanation:

1. Make a fraction with the total number of cards at the bottom (60) and all the cards that are not green (aka yellow and blue) on top (42). Then simplify the fraction 42/60 by dividing both terms by 6 to get 7/10

2. For this one, first find how many students out of the first 80 liked basketball by subtracting the 60 students who liked other sports from 80. This gives you 20. Now you know that 20/80 students like basketball. Now simplify the fraction to get 1/4. Then find 1/4 of 100, because we know that 1/4 of students like basketball. 1/4 of 100 is 25.

3. This problem is exactly the same as number 1, except instead of adding all the other colors and putting them as a fraction over the total, just put the number of pink shirts over the total number of shirts to get 3/12. Then simplify it to 1/4, and that's your answer.

4. This is also similar to problems 1 and 3. Just put the number of heads coin tosses over the total and simplify it.

5. This one is very similar to all the problems so far. I will let you do this one on your own. Remember: The number of cases (rolls or colors or sports or cards etc.) that you want to find the probability for goes on top, and the total number of those things goes on the bottom. The bigger the fraction, the greater probability there is.

Note: Please only ask one question at a time on here instead of 5 at once. Since these problems are so similar, chances are, you could have figured them out on your own with a little help on one of them. You are more likely to get a quick answer if the answerer doesn't have to do as much work.

4 0

3 years ago