a) \(\frac{234}{585}-\frac{51}{85}=\frac{2}{5}-\frac{3}{5}=\frac{-1}{5}\)
b) \(\frac{364}{-1820}+\frac{-276}{46}-\frac{-52}{46}=\frac{-1}{5}+6+\frac{52}{46}=\frac{-1}{5}+\frac{30}{5}+\frac{26}{23}=\frac{29}{5}+\frac{26}{23}=\frac{667}{115}+\frac{130}{115}=\frac{797}{115}\)
c) \(\frac{-1616}{3232}-\frac{70}{-105}-\frac{186}{217}=\frac{-1}{2}+\frac{70}{105}-\frac{6}{7}=\frac{-1}{2}+\frac{2}{3}+\frac{-6}{7}=\frac{-21}{42}+\frac{28}{42}+\frac{-36}{42}=\frac{7}{42}+\frac{-36}{42}=\frac{-29}{42}\)
d) \(\frac{375}{-450}-\frac{-216}{252}-\frac{448}{-640}=\frac{-5}{6}+\frac{216}{252}+\frac{448}{640}=\frac{-5}{6}+\frac{6}{7}+\frac{7}{10}=\frac{-175}{210}+\frac{180}{210}+\frac{147}{210}=\frac{5}{210}+\frac{147}{210}=\frac{152}{210}=\frac{76}{105}\)
