In the expression $3x$, what is the $3$? So this is quite a simple question. I KNOW I learnt this before, but can't for the life of me figure out or find anywhere that refers to the definition I'm looking for. Look at the expression
$$
3x
$$
In this expression, what is the $3$ in this context? The $3$ 'prefixes' the $x$, but I don't believe that it is called a prefix of $x$.

A "scalar" in contex of Algebra.
Could be  also a "coefficient".
