[tex]\displaystyle 6\frac{3}{17}:(\frac{5}{17}-1)-2*4\frac{1}{2}=\frac{105}{17}:(-\frac{12}{17})-2*\frac{9}{2}=-\frac{105}{17}*\frac{17}{12}-9=-35*\frac{1}{4}-9=\\\\-\frac{35}{4}-9=-\frac{71}{4}[/tex]