Which identity is $y \cdot 3 = 3 \cdot y$ $y3=3y$ ?

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Answer 1 · 2015-06-17T09:21:21

Commutativity of multiplication

$a \cdot b = b \cdot a$ $a*b = b*a$ for all $a, b in RR$

Both addition and multiplication are (normally) commutative.

There are some strange number systems in which multiplication is not always commutative (quaternions).

Which identity is y*3=3*yy⋅3=3⋅yy*3=3*y?