Question

What is the sum of the matrices shown below?

3
6 0
9
5 -2
+
6
0
-8 4
=

Answer 1

Option 2

Explanation:

`\begin{bmatrix} 3+6 & 9+0 \\ 5-8 & -2+4 \end{bmatrix}=\begin{bmatrix} 9 & 9 \\ -3 & 2 \end{bmatrix}`

Answer 2

(b)

Explanation:

You want the sum of the given matrices.

Matrix sum

The sum of two matrices is the matrix of the sums of corresponding terms.

Here, we observe that we can choose the correct answer by finding the bottom right term. The sum of bottom right terms is -2+4 = 2. The only answer choice with that value at bottom right is the second answer choice.

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Additional comment

You need to know how to work the problem, but you don't actually need to work the whole problem in order to make the correct answer choice. (This is often the case with multiple choice questions, so it pays to look before you leap.)