[tex]a+b+c=81 \\ a:b=4 \to \boxed{a=4b} \\ c:b= 2 \ r \ 4 \to \boxed{c=2b+4} \\ ******************* \\ 4b+b+2b+4=81 \\ 7b+4=81 \\ 7b=81- 4\\ 7b=77 /:7 \\ \boxed{\bold{b=11}} \\ \\ a=4b =\ \textgreater \ \boxed{\bold{a=44}} \\ \\ c=2b+4=\ \textgreater \ \boxed{\bold{c=26}}[/tex]
