Bài 1: Tính hợp lý:
a) Ta có: \(\frac{-3}{17}+\frac{8}{13}+\frac{-14}{17}\)
\(=\left(\frac{-3}{17}+\frac{-14}{17}\right)+\frac{8}{13}\)
\(=\frac{-17}{17}+\frac{8}{13}=-1+\frac{8}{13}=\frac{-13}{13}+\frac{8}{13}=-\frac{5}{13}\)
b) Ta có: \(\frac{-5}{24}+\frac{12}{36}+\frac{11}{-24}\)
\(=\left(\frac{-5}{24}+\frac{-11}{24}\right)+\frac{1}{3}\)
\(=\frac{-2}{3}+\frac{1}{3}=\frac{-1}{3}\)
c) Ta có: \(\frac{-7}{18}+\left(\frac{3}{-4}+\frac{11}{-18}\right)\)
\(=\frac{-7}{18}+\frac{-3}{4}+\frac{-11}{18}\)
\(=\frac{-7-11}{18}+\frac{-3}{4}\)
\(=-1+\frac{-3}{4}\)
\(=\frac{-4}{4}+\frac{-3}{4}=-\frac{7}{4}\)
d) Ta có: \(\frac{9}{23}+\frac{5}{-8}+\frac{-15}{41}+\frac{14}{23}+\frac{-26}{41}\)
\(=\left(\frac{9}{23}+\frac{14}{23}\right)+\left(\frac{-15-26}{41}\right)+\frac{-5}{8}\)
\(=1+\left(-1\right)+\frac{-5}{8}=\frac{-5}{8}\)
