Answer :
To solve the matrix equation
[tex]\[ \begin{pmatrix} \frac{1}{2} & -\frac{1}{4} \\ 2 & -\frac{3}{4} \end{pmatrix} \begin{pmatrix} x \\ y \end{pmatrix} = \begin{pmatrix} 2 & -4 \\ 1 & 6 \end{pmatrix}, \][/tex]
we need to find the inverse of the matrix
[tex]\[ A = \begin{pmatrix} \frac{1}{2} & -\frac{1}{4} \\ 2 & -\frac{3}{4} \end{pmatrix}. \][/tex]
Let's denote the matrix on the right-hand side as [tex]\( B \)[/tex]:
[tex]\[ B = \begin{pmatrix} 2 & -4 \\ 1 & 6 \end{pmatrix}. \][/tex]
### Step 1: Calculate the inverse of matrix [tex]\(A\)[/tex]
Given [tex]\( A = \begin{pmatrix} \frac{1}{2} & -\frac{1}{4} \\ 2 & -\frac{3}{4} \end{pmatrix} \)[/tex],
the inverse of [tex]\( A \)[/tex] is
[tex]\[ A^{-1} = \begin{pmatrix} -6 & 2 \\ -16 & 4 \end{pmatrix}. \][/tex]
### Step 2: Find the matrix solution [tex]\(X\)[/tex]
To solve for [tex]\(X\)[/tex], we use the equation:
[tex]\[ A^{-1} A \begin{pmatrix} x \\ y \end{pmatrix} = A^{-1} B. \][/tex]
Since [tex]\( A^{-1} A = I \)[/tex] (where [tex]\( I \)[/tex] is the identity matrix), the left-hand side simplifies to
[tex]\[ I \begin{pmatrix} x \\ y \end{pmatrix} = \begin{pmatrix} x \\ y \end{pmatrix}. \][/tex]
Therefore,
[tex]\[ \begin{pmatrix} x \\ y \end{pmatrix} = A^{-1} B. \][/tex]
### Step 3: Calculate [tex]\( A^{-1} B \)[/tex]
Multiplying the inverse of [tex]\( A \)[/tex] by [tex]\( B \)[/tex]:
[tex]\[ A^{-1} B = \begin{pmatrix} -6 & 2 \\ -16 & 4 \end{pmatrix} \begin{pmatrix} 2 & -4 \\ 1 & 6 \end{pmatrix} = \begin{pmatrix} -10 & 36 \\ -28 & 88 \end{pmatrix}. \][/tex]
So the matrix solution [tex]\(X\)[/tex] is
[tex]\[ X = \begin{pmatrix} x \\ y \end{pmatrix} = \begin{pmatrix} -10 & 36 \\ -28 & 88 \end{pmatrix}. \][/tex]
Thus, we can summarize our solution to the matrix equation as
[tex]\[ \begin{pmatrix} x \\ y \end{pmatrix} = \begin{pmatrix} -10 & 36 \\ -28 & 88 \end{pmatrix}. \][/tex]
[tex]\[ \begin{pmatrix} \frac{1}{2} & -\frac{1}{4} \\ 2 & -\frac{3}{4} \end{pmatrix} \begin{pmatrix} x \\ y \end{pmatrix} = \begin{pmatrix} 2 & -4 \\ 1 & 6 \end{pmatrix}, \][/tex]
we need to find the inverse of the matrix
[tex]\[ A = \begin{pmatrix} \frac{1}{2} & -\frac{1}{4} \\ 2 & -\frac{3}{4} \end{pmatrix}. \][/tex]
Let's denote the matrix on the right-hand side as [tex]\( B \)[/tex]:
[tex]\[ B = \begin{pmatrix} 2 & -4 \\ 1 & 6 \end{pmatrix}. \][/tex]
### Step 1: Calculate the inverse of matrix [tex]\(A\)[/tex]
Given [tex]\( A = \begin{pmatrix} \frac{1}{2} & -\frac{1}{4} \\ 2 & -\frac{3}{4} \end{pmatrix} \)[/tex],
the inverse of [tex]\( A \)[/tex] is
[tex]\[ A^{-1} = \begin{pmatrix} -6 & 2 \\ -16 & 4 \end{pmatrix}. \][/tex]
### Step 2: Find the matrix solution [tex]\(X\)[/tex]
To solve for [tex]\(X\)[/tex], we use the equation:
[tex]\[ A^{-1} A \begin{pmatrix} x \\ y \end{pmatrix} = A^{-1} B. \][/tex]
Since [tex]\( A^{-1} A = I \)[/tex] (where [tex]\( I \)[/tex] is the identity matrix), the left-hand side simplifies to
[tex]\[ I \begin{pmatrix} x \\ y \end{pmatrix} = \begin{pmatrix} x \\ y \end{pmatrix}. \][/tex]
Therefore,
[tex]\[ \begin{pmatrix} x \\ y \end{pmatrix} = A^{-1} B. \][/tex]
### Step 3: Calculate [tex]\( A^{-1} B \)[/tex]
Multiplying the inverse of [tex]\( A \)[/tex] by [tex]\( B \)[/tex]:
[tex]\[ A^{-1} B = \begin{pmatrix} -6 & 2 \\ -16 & 4 \end{pmatrix} \begin{pmatrix} 2 & -4 \\ 1 & 6 \end{pmatrix} = \begin{pmatrix} -10 & 36 \\ -28 & 88 \end{pmatrix}. \][/tex]
So the matrix solution [tex]\(X\)[/tex] is
[tex]\[ X = \begin{pmatrix} x \\ y \end{pmatrix} = \begin{pmatrix} -10 & 36 \\ -28 & 88 \end{pmatrix}. \][/tex]
Thus, we can summarize our solution to the matrix equation as
[tex]\[ \begin{pmatrix} x \\ y \end{pmatrix} = \begin{pmatrix} -10 & 36 \\ -28 & 88 \end{pmatrix}. \][/tex]