I don't understand the meaning of commute and i can't find any info about it

Question

Might be duplicate I don't know but Properties of a binary operator; trouble understanding question.
begin{equation*}
        begin{array}{c}
            star : mathbb{Z} times mathbb{Z} to mathbb{Z}\
            x star y = x + 3y
        end{array}
    end{equation*}
(d.) Can you find two integers a and b that commute for $star$? Explain.

Christoph · Accepted Answer

Two integers $a$ and $b$ commute under (or for) $star$ if $astar b=bstar a$.
So we are looking for integers $a,b$ such that
$$
a+3b = b+3a.
$$

user822251 · Answer

Any operation $star$ commutes if $a star b = b star a$. An example of an operation that does not commute would be a matrix multiplication since if $A$ and $B$ are matrices, it is possible that $A cdot B neq B cdot A$, thus the $cdot$ operation is not commutative.

Answered by user822251 on November 7, 2020

I don't understand the meaning of commute and i can't find any info about it

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