Explanation:
A Given,
\(\mathrm{R}=\{(\mathrm{a}, \mathrm{b}): \mathrm{b}=\mathrm{a}-1, \mathrm{a} \in \mathrm{Z}, 5\lt \mathrm{a}\lt 9\} \text {, }\)
\(\because \quad \mathrm{a}=6,7,8\)
\(\therefore \quad \mathrm{a}=6, \mathrm{~b}=6-1=5\)
\(\mathrm{a}=7, \mathrm{~b}=7-1=6\)
\(\mathrm{a}=8, \mathrm{~b}=8-1=7\)
\(\mathrm{R}=(6,5),(7,6)(8,7)\)
So, range of \(R=\{5,6,7\}\)