\(\frac{5}{4}\)+\(\frac{-12}{7}\)=\(\frac{5.\left(-12\right)}{4.7}\)=\(\frac{-15}{7}\)
b)\(\frac{-4}{3}\):\(\frac{13}{9}\)=\(\frac{-4}{3}\).\(\frac{9}{13}\)=\(\frac{-4.9}{3.13}\)=\(\frac{-12}{13}\)
c)\(\frac{-5}{7}.\frac{49}{3}:\frac{7}{-6}\)=\(\frac{-5}{7}.\frac{49}{3}.\frac{-6}{7}\)=\(\frac{5.49.6}{7.3.7}\)=10
d)\(\left(-\frac{9}{25}\right):6\)=\(\frac{-9}{25.6}=\frac{-3}{50}\)