Solve for the variables [tex]\( x \)[/tex], [tex]\( y \)[/tex], and [tex]\( z \)[/tex] given the matrix equation:

[tex]\[ \left[\begin{array}{cc} 2x & 4 \\ -5 & 8 \end{array}\right] = \left[\begin{array}{cc} -4 & y+1 \\ z & 8 \end{array}\right] \][/tex]



Answer :

Let's solve the problem step-by-step.

We are given two matrices that are set equal to each other:
[tex]\[ \left[\begin{array}{cc} 2x & 4 \\ -5 & 8 \end{array}\right] = \left[\begin{array}{cc} -4 & y+1 \\ z & 8 \end{array}\right] \][/tex]

Our goal is to find the values of [tex]\( x \)[/tex], [tex]\( y \)[/tex], and [tex]\( z \)[/tex] such that the entries of the matrices are equal. We will do this by equating the corresponding elements of the two matrices.

### Step-by-Step Solution

1. Compare the element at the first row, first column:
[tex]\[ 2x = -4 \][/tex]
To solve for [tex]\( x \)[/tex], divide both sides by 2:
[tex]\[ x = \frac{-4}{2} \][/tex]
[tex]\[ x = -2 \][/tex]

2. Compare the element at the first row, second column:
[tex]\[ 4 = y + 1 \][/tex]
To isolate [tex]\( y \)[/tex], subtract 1 from both sides:
[tex]\[ 4 - 1 = y \][/tex]
[tex]\[ y = 3 \][/tex]

3. Compare the element at the second row, first column:
[tex]\[ -5 = z \][/tex]
This directly gives:
[tex]\[ z = -5 \][/tex]

4. Compare the element at the second row, second column:
[tex]\[ 8 = 8 \][/tex]
This is already satisfied and doesn't provide any new information.

### Final Values

By solving the equations, we have found the values of the variables:
[tex]\[ x = -2, \quad y = 3, \quad z = -5 \][/tex]

These values satisfy the equality of the given matrices.