Answer:
The equation is given below as
[tex]r-7=91[/tex]Concept:
To get the value of r, collect similar terms by adding 7 to both sides
[tex]\begin{gathered} r-7=91 \\ r-7+7=91+7 \\ r=98 \end{gathered}[/tex]Hence,
The final answer is
[tex]r=98[/tex]