13/17 : 2/5 - 11/7 : 2/5 = ( 13/17- 11/7 ) : 2/5
=(91/119 - 187/119) : 2/5
= -96/119 : 2/5
= -96/119 x 5/2
= -240/119
\(\frac{13}{17}:\frac{2}{5}-\frac{11}{7}:\frac{2}{5}\)
\(=\frac{13}{17}.\frac{5}{2}-\frac{11}{7}.\frac{5}{2}\)
\(=\frac{5}{2}.\left(\frac{13}{17}-\frac{11}{7}\right)\)
\(=\frac{5}{2}.\frac{-96}{119}\)
\(=\frac{-240}{119}\)