Answer
$(5q+2r)+s$
Work Step by Step
The associative property of addition holds that $(a+b)+c=a+(b+c)$.
In this example, we can set $a+(b+c)=5q+(2r+s)$.
Therefore, $a=5q$, $b=2r$, and $c=s$, so an equivalent expression would be $(a+b)+c=(5q+2r)+s$.