Question

HELP PLEASE .........

Answer 1

Option 2 is the right answer.

Explanation:

The matrix equation is given by, AX + B = C.

AX = C - B =
`\left[\begin{array}{ccc}-42&-20\\5&4\end{array}\right] - \left[\begin{array}{ccc}-7&-9\\4&-1\end{array}\right] = \left[\begin{array}{ccc}-35&-11\\1&5\end{array}\right]`.

Let X =
`\left[\begin{array}{ccc}x&y\\z&t\end{array}\right]`.

Hence, AX =
`\left[\begin{array}{ccc}-3&-4\\1&0\end{array}\right] \left[\begin{array}{ccc}x&y\\z&t\end{array}\right] = \left[\begin{array}{ccc}-3x - 4z&-3y - 4t\\x&y\end{array}\right]`.

As per the above equation, x = 1, y = 5.

`-3x - 4z = -35\\ -4z = - 32\\z = 8`.

`-3y - 4t = -11\\-4t = 4\\t = -1`.

X =
`\left[\begin{array}{ccc}1&5\\8&-1\end{array}\right]`