Question

Determine the value of the following if it is possible. If it is not possible, explain.

Answer 1

Option B:

`=\left(\begin{array}{cc}4 & 2 \\1 & 4 \\3 & -4\end{array}\right)`

Solution:

Given data:

`\left[\begin{array}{cc}3 & 2 \\-4 & 6 \\7 & 5\end{array}\right]-\left[\begin{array}{cc}-1 & 0 \\-5 & 2 \\4 & 9\end{array}\right]`

Subtract the element in the corresponding positions.

That is subtract first column of 1st matrix with first column of 2nd matrix

Next, subtract second column of 1st matrix with second column of 2nd matrix

`\left[\begin{array}{cc}3 & 2 \\-4 & 6 \\7 & 5\end{array}\right]-\left[\begin{array}{cc}-1 & 0 \\-5 & 2 \\4 & 9\end{array}\right]=\left(\begin{array}{cc}3-(-1) & 2-0 \\(-4)-(-5) & 6-2 \\7-4 & 5-9\end{array}\right)`

Now, simplifying each element, we get

`=\left(\begin{array}{cc}3+1 & 2-0 \\-4+5 & 6-2 \\7-4 & 5-9\end{array}\right)`

`=\left(\begin{array}{cc}4 & 2 \\1 & 4 \\3 & -4\end{array}\right)`

The value of the given is
`\left(\begin{array}{cc}4 & 2 \\1 & 4 \\3 & -4\end{array}\right)`.

Option B is the correct answer.