To evaluate \( 3xy \) for \( x = 1 \) and \( y = 2 \), you can substitute the values of \( x \) and \( y \) into the expression:
\[ 3xy = 3 \cdot (1) \cdot (2) \]
Now, perform the multiplication:
\[ 3 \cdot 1 = 3 \] \[ 3 \cdot 2 = 6 \]
Thus, \( 3xy = 6 \).