Find the measure of angle X in the figure below: 35 47 51 62

Solve for XX. Assume XX is a 2×22×2 matrix and II denotes the 2×22×2 identity matrix. Do not use decimal numbers in your answer.

sveticcg [70]

The question is incomplete. The complete question is as follows:

Solve for X. Assume X is a 2x2 matrix and I denotes the 2x2 identity matrix. Do not use decimal numbers in your answer. If there are fractions, leave them unevaluated.

$\left[\begin{array}{cc}2&8\\-6&-9\end{array}\right]$ · X· $\left[\begin{array}{ccc}9&-3\\7&-6\end{array}\right]$ =I.

First, we have to identify the matrix I. As it was said, the matrix is the identiy matrix, which means

I = $\left[\begin{array}{ccc}1&0\\0&1\end{array}\right]$

So, $\left[\begin{array}{cc}2&8\\-6&-9\end{array}\right]$ · X· $\left[\begin{array}{ccc}9&-3\\7&-6\end{array}\right]$ = $\left[\begin{array}{ccc}1&0\\0&1\end{array}\right]$

Isolating the X, we have

X· $\left[\begin{array}{ccc}9&-3\\7&-6\end{array}\right]$ = $\left[\begin{array}{cc}2&8\\-6&-9\end{array}\right]$ - $\left[\begin{array}{ccc}1&0\\0&1\end{array}\right]$

Resolving:

X· $\left[\begin{array}{ccc}9&-3\\7&-6\end{array}\right]$ = $\left[\begin{array}{ccc}2-1&8-0\\-6-0&-9-1\end{array}\right]$

X· $\left[\begin{array}{ccc}9&-3\\7&-6\end{array}\right]$ = $\left[\begin{array}{ccc}1&8\\-6&-10\end{array}\right]$

Now, we have a problem similar to A.X=B. To solve it and because we don't divide matrices, we do X=A⁻¹·B. In this case,

X= $\left[\begin{array}{ccc}9&-3\\7&-6\end{array}\right]$ ⁻¹· $\left[\begin{array}{ccc}1&8\\-6&-10\end{array}\right]$

Now, a matrix with index -1 is called Inverse Matrix and is calculated as: A . A⁻¹ = I.

So,

$\left[\begin{array}{ccc}9&-3\\7&-6\end{array}\right]$ · $\left[\begin{array}{ccc}a&b\\c&d\end{array}\right]$ = $\left[\begin{array}{ccc}1&0\\0&1\end{array}\right]$

9a - 3b = 1

7a - 6b = 0

9c - 3d = 0

7c - 6d = 1

Resolving these equations, we have a= $\frac{2}{11}$ ; b= $\frac{7}{33}$ ; c= $\frac{-1}{11}$ and d= $\frac{-3}{11}$ . Substituting:

X= $\left[\begin{array}{ccc}\frac{2}{11} &\frac{-1}{11} \\\frac{7}{33}&\frac{-3}{11} \end{array}\right]$ · $\left[\begin{array}{ccc}1&8\\-6&-10\end{array}\right]$

Multiplying the matrices, we have

X= $\left[\begin{array}{ccc}\frac{8}{11} &\frac{26}{11} \\\frac{39}{11}&\frac{198}{11} \end{array}\right]$

6 0

3 years ago

Show the tens fact you used. Write the difference. 12-7= 10- _=

Maksim231197 [3]

12-7=5

10-5=5

is that what you where looking for?

5 0

2 years ago

Hope u can do it HELP MATH

Nostrana [21]

Answer:

the right answer would be 13

5 0

2 years ago

Read 2 more answers

Kyla has the number of cherries that Denise has. If Kyla has 46 cherries, how many cherries do they have altogether?

pogonyaev

Answer:

92

Step-by-step explanation:

46 + 46 = 92

5 0

1 year ago

Read 2 more answers

The school librarian, Mr. Marker, knows the library has 1,400 books but wants to reorganize how the books are displayed on the s

kipiarov [429]

Answer:

200 resource books

800 fiction books

400 nonfiction books

Step-by-step explanation:

Let's define x as the amount of resource books that are in the library. As he has four times as many fiction books as resource books, that means he has 4*x fiction books.

We also know he has half as many nonfiction books as fiction books, that is 1/2*4*x = 2*x nonfiction books.

We just need to find out the value of x.

We know there are 1,400 books in total and there are just 3 types of books. Therefore, if we sum all of them, we get the 1,400.

Written in math language, that is

x + 4x + 2x = 1,400

7x = 1,400

We divide by 7 on both sides and we get

7/7x = 1,400/7

x = 200

Now we replace the x with 200 to know how many books he has of each type:

Resource books = x = 200

Fiction books = 4*x = 4*200 = 800

Nonfiction books = 2*x = 2*200 = 400

Therefore, there are 200 resource books, 800 fiction books and 400 nonfiction books in the library.

The tape diagram is attached as an image.

8 0

2 years ago