Bài 2. Tính:

a) $(-0.5)-(-1+\frac{2}{3})/1.5+(\frac{-1}{4})$

b) $[(\frac{-7}{8}/\frac{21}{16}]-\frac{5}{3}\times(\frac{1}{3}-\frac{7}{10})$

c) $[(\frac{-2}{3}+\frac{3}{4}]^{2}\times\frac{12}{5}-\frac{1}{5}$

d) $(\frac{1}{25}-0.4)^{2}/\frac{9}{125}-[(1\frac{1}{3}-\frac{2}{5})\times\frac{3}{7}]$

e) ${3\frac{17}{18}\times[\frac{5}{2}-(\frac{1}{3}+\frac{2}{9}]}/[(\frac{-1}{2})+0.25]^{2}$

Bài 4. Tìm x, biết:

a) $x+\frac{3}{7}=\frac{2}{5}$

b)$\frac{3}{2}-x=\frac{4}{5}$

c)$\frac{5}{9}-\frac{1}{3}x=\frac{2}{3}$

d) $\frac{3}{5}x-1\frac{1}{5}=\frac{-3}{14}/\frac{5}{7}$