Answer
Associative Property of Multiplication
Work Step by Step
RECALL:
The associative property of multiplication states that for any real numbers $a, b,$ and $c$,
$(a \cdot b) \cdot c = a \cdot (b \cdot c)$
$(6\cdot9)\cdot3=6\cdot(3\cdot9)$
Thus, the given expression illustrates the associative property of multiplication.