What is ab+ba? and xz+zx ab + ba ​

Question

What is ab+ba?
and xz+zx

`ab + ba`
​

Answer 1

Answers: 1) " 2ab ".
2) " 2xz ".

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Explanation:

ab + ba = ab + ab = 1ab + 1ab = (1+1)*ab = 2ab .

xz + zx = xz + xz = 1xz + 1xz = (1+1)*xz = 2xz.

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