\(a.\frac{-12121212}{-30303030}=\frac{12121212}{30303030}=\frac{12121212:1010101}{30303030:1010101}=\frac{12}{30}=\)\(\frac{2}{5}\)
\(b.\frac{13.34-13.15}{19.29+19.10}=\frac{13.\left(34-15\right)}{19.\left(29+10\right)}=\frac{13.19}{19.39}=\frac{1}{3}\)
\(c.\frac{45.26-26.24}{21.91-21.13}=\frac{26.\left(45-24\right)}{21.\left(91-13\right)}=\frac{26.21}{21.78}=\frac{1}{3}\)
\(d.\frac{47.5}{-35.33-35.14}=\frac{47.5}{-35.\left(33+14\right)}=\frac{47.5}{-35.47}=\frac{-1}{7}\)
\(e.\frac{-15.34-15.46}{80}\frac{-15.\left(34+46\right)}{80}=\frac{-15.80}{80}=-15\)