Tính a) -3 3/4 + -10/25 + -6/12 b) 4 - 1 2/5 - 8/3

* Hướng dẫn giải

a) $-3\frac{3}{4}+\frac{-10}{25}+\frac{-6}{12}=\frac{-15}{4}+\frac{-2}{5}+\frac{-1}{2}$$=\frac{-75}{20}+\frac{-8}{20}+\frac{-10}{20}=\frac{-93}{20}$

b) $4-1\frac{2}{5}-\frac{8}{3}=4-\frac{7}{5}-\frac{8}{3}=\frac{60}{15}-\frac{21}{15}-\frac{40}{15}=\frac{-1}{15}$