Answer
$(9y+x)+3z$
Work Step by Step
The associative property holds that $(a+b)+c=a+(b+c)$, where a, b, and c are real numbers.
In this example, we can set $a+(b+c)=9y+(x+3z)$.
So, $a=9y$, $b=x$, and $c=3z$.
Therefore, the other side of this equation is $(a+b)+c=(9y+x)+3z$.