\(\dfrac{11}{19}\times\dfrac{13}{17}+\dfrac{8}{19}\times\dfrac{13}{7}\\ =\dfrac{143}{323}+\dfrac{104}{133}\\ =\dfrac{2769}{2261}\)
\(11/19.13/17+8/19.13/17\)
\(=\dfrac{13}{17}\left(\dfrac{11}{19}+\dfrac{8}{19}\right)\)
\(=\dfrac{3}{17}.1=\dfrac{3}{17}\)
\(\dfrac{11}{19}.\dfrac{13}{17}+\dfrac{8}{19}.\dfrac{13}{7}\Rightarrow\dfrac{11}{19}.\dfrac{13}{17}+\dfrac{8}{19}.\dfrac{13}{17}\\ =\dfrac{13}{17}\left(\dfrac{11}{19}+\dfrac{8}{19}\right)\\ =\dfrac{13}{17}.1\\ =\dfrac{13}{17}\)