Question 28714
Let x = Diophantus' age.


1/6x + 1/12x +1/7x +1/2x + 5 + 4 = x
9 = -1/6x -1/12x -1/7x -1/2x + x
9 = 9/84x
756 = 9x
84 = x


I hope that is right?