[tex]a + b + c = 86\\a - 5 = b + 4 = \frac{c}{3} \\\\a - 5 = b + 4 \rightarrow a = b + 4 + 5 \rightarrow a = b + 9\\b + 4 = \frac{c}{3} \rightarrow 3(b+4) = c \rightarrow c = 3b + 12\\\\a + b + c = 86\\b + 9 + b + 3b + 12 = 86 \rightarrow 5b + 21 = 86 \rightarrow 5b = 86 - 21 = 65 \rightarrow b = \frac{65}{5} = 13\\\\a = b + 9 = 13 + 9 = 22\\c = 3b + 12 = 3 \times 13 + 12 = 39 + 12 = 51\\\\a = 22\\b = 13\\c = 51[/tex]
