a: \(19\frac58:\frac{7}{12}-15\frac14:\frac{7}{12}\)
\(=\left(19+\frac58-15-\frac14\right):\frac{7}{12}\)
\(=\left(4+\frac58-\frac14\right):\frac{7}{12}=\left(4+\frac38\right)\cdot\frac{12}{7}\)
\(=\frac{35}{8}\cdot\frac{12}{7}=\frac{35}{7}\cdot\frac{12}{8}=5\cdot\frac32=\frac{15}{2}\)
c: \(\left(3\frac13+2,5\right):\left(3\frac16-4\frac15\right)-\frac{11}{31}\)
\(=\left(3+\frac13+\frac52\right):\left(3+\frac16-4-\frac15\right)-\frac{11}{31}\)
\(=\left(\frac{18}{6}+\frac26+\frac{15}{6}\right):\left(-1+\frac16-\frac15\right)-\frac{11}{31}\)
\(=\frac{35}{6}:\left(-\frac{30}{30}+\frac{5}{30}-\frac{6}{30}\right)-\frac{11}{31}\)
\(=\frac{35}{6}:\frac{-31}{30}-\frac{11}{31}=\frac{35}{6}\cdot\frac{-30}{31}-\frac{11}{31}=\frac{-175}{31}-\frac{11}{31}=-\frac{186}{31}=-6\)
e: \(\frac{18}{37}+\frac{8}{24}+\frac{19}{37}-1\frac{23}{24}+\frac23\)
\(=\left(\frac{18}{37}+\frac{19}{37}\right)+\left(\frac13+\frac23\right)-1-\frac{23}{24}\)
\(=1+1-1-\frac{23}{24}=1-\frac{23}{24}=\frac{1}{24}\)
