=26/7+(-5/7).4/13+9/13
=(20/7+-5/7).(4/13+9/13)
=15/7.13/13
=15/7.1
=15/7
\(\frac{26}{7}+\frac{-5}{7}.\frac{4}{13}+\frac{-5}{7}.\frac{9}{13}\text{ }\)
\(=\frac{26}{7}+\left[\frac{-5}{7}.\left(\frac{4}{14}+\frac{9}{13}\right)\right]\)
\(=\frac{26}{7}+\left[\frac{-5}{7}.\frac{13}{13}\right]\)
\(=\frac{26}{7}+\left[\frac{-5}{7}.1\right]\)
\(=\frac{26}{7}+\frac{-5}{7}\)
\(=\frac{21}{7}\)
\(=3\)
\(-\dfrac{5}{7}\left(\dfrac{4}{13}+\dfrac{9}{13}\right)+\dfrac{26}{7}=-\dfrac{5}{7}+\dfrac{26}{7}=\dfrac{21}{7}=3\)