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प्रश्न
Determine whether the following operation define a binary operation on the given set or not : 'O' on Z defined by a O b = ab for all a, b ∈ Z.
उत्तर
Both a = 3 and b = -1 belong to Z.
⇒ a * b = 3-1
=`1/3` ∉ Z
Thus, * is not a binary operation on Z.
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