Answer :
Given : Brooke solve equation 6r=72
6r-6=72-6
r=66
Find: why Brooke solution is wrong.
Explanation:
[tex]\begin{gathered} 6r=72 \\ 6r-6=72-6 \\ 6(r-1)=66 \\ r-1=11 \\ r=11+1 \\ r=12 \end{gathered}[/tex]Final answer: the required value of r is 12.