[tex]15:3\frac{12}{17} =2\frac{5}{17} +4\frac{1}{5} -2\frac{3}{5}\\\\15: \frac{63}{17} =\frac{39}{17} +\frac{21}{5} -\frac{13}{5} \\\\\frac{15}{1} *\frac{17}{63} =\frac{39}{17} +\frac{8}{5} \\\\\frac{85}{21} =\frac{195}{85} +\frac{136}{85} \\\\\frac{85}{21} =\frac{331}{85} \\\\7225\neq 6951[/tex]