For each operation defined below, determine whether is binary, commutative or associative.

On Z+, define a b = ab


It is given that On Z+, define a b = ab

abϵ Z+, so operation * is binary


We know that ab = ba for a, b ϵ Z+


1 * 2 =12 and 2 * 1 = 21 =2


1 * 2 ≠ 2 *1, where 1,2 ϵ Z+


The operation * is not commutative.


Also, we get,


(1 * 2) * 3 = 23 *3 = 8 * 3 = 24


1 * (2 * 3) = 1 * 32 = 1 * 9 = 9


(1 * 2) * 3 ≠ 1 * (2 * 3), where 1,2,3 ϵ Z+


The operation * is not associative.


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