The student added the individual row elements of each matrix together.
Work Step by Step
This doesn't work since the matrices are not the same. The second matrix should be a 2x2 matrix (instead of a 1x1 matrix).
You can help us out by revising, improving and updating this answer.Update this answer
After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.