\(\dfrac{15}{19}.\dfrac{27}{33}+\dfrac{15}{19}.\dfrac{19}{33}-\dfrac{15}{19}.\dfrac{13}{33}\)
= \(\dfrac{15}{19}.\left(\dfrac{27}{33}+\dfrac{19}{33}-\dfrac{13}{33}\right)\)
= \(\dfrac{15}{19}.1=\dfrac{15}{19}\)
\(=\dfrac{15}{19}.\left(\dfrac{27}{33}+\dfrac{19}{33}-\dfrac{13}{33}\right)\)
\(=\dfrac{15}{19}.\dfrac{33}{33}\)
\(=\dfrac{15}{19}\)
a)\(=\dfrac{15}{19}.(\dfrac{27}{33}+\dfrac{19}{33}-\dfrac{13}{33})\)
\(=\dfrac{15}{19}.1\)
\(=\dfrac{15}{19}\)

