\(-\frac{315}{540}=-\frac{7}{12}\)
\(\frac{25.13}{26.35}=\frac{5.5.13}{13.2.7.5}=\frac{5}{14}\)
\(\frac{6.9-2.17}{63.3-119}=\frac{2\left(27-17\right)}{7\left(27-17\right)}=\frac{2}{7}\)
\(\frac{1989.1990+3978}{1992.1991-3984}=\frac{1989\left(1990+2\right)}{1992\left(1991-2\right)}=\frac{1989.1992}{1992.1989}=1\)