17/15 x 4/11 + 8/15 x 4/11
= 4/11 x (17/15 + 8/15)
= 4/11 x 5/3
= 20/33
\(\frac{13}{19}\times\left(\frac{19}{13}-\frac{7}{9}\right)\)
\(=\frac{13}{19}\times\frac{19}{13}-\frac{13}{19}\times\frac{7}{9}\)
\(=1-\frac{117}{361}\)
\(=\frac{244}{361}\)
\(\frac{17}{15}\times\frac{4}{11}+\frac{8}{15}\times\frac{4}{11}\)
\(=\frac{4}{11}\times\left(\frac{17}{15}+\frac{8}{15}\right)\)
\(=\frac{4}{11}\times\frac{5}{3}\)
\(=\frac{20}{33}\)