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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?

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 represe class=

Respuesta :

sqdancefan

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

[tex] 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] [/tex]

Answer:

C= 1   1

    3  2

Step-by-step explanation: