To simplify the fraction \(-100/5\), you divide \(-100\) by \(5\):
\[ -100 \div 5 = -20 \]
Thus, the simplified value of \(-100/5\) is \(-20\).
If you're looking for a set of numbers that includes \(-20\), any set that has \(-20\) as one of its elements would work. For example, the set \({-50, -20, 0, 10}\) includes the simplified value.