\(78\cdot15-\frac{28}{50}+78\cdot14\)
\(=78\cdot\left(15-14\right)+\frac{14}{25}\)
\(=78\cdot1+\frac{14}{25}\)
\(=78+\frac{14}{25}=78\frac{14}{25}\)
\(78\times15-\frac{28}{50}+78\times14.\)
\(=78\times\left(15+14\right)-\frac{28}{50}\)
\(=78\times29-\frac{28}{50}\)
\(=2262-\frac{28}{50}\)
\(=\frac{56536}{25}\)