Tìm x, biết:

a) $x + \frac{3}{7} = \frac{2}{5}$ suy ra $x = \frac{2}{5} - \frac{3}{7} = - \frac{1}{35}$

b) $\frac{3}{2} - x = \frac{4}{5}$ suy ra $x = \frac{7}{10}$

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

d) $\frac{3}{5} x - 1 \frac{1}{5} = \frac{- 3}{14} / \frac{5}{7}$ suy ra $\frac{3}{5} x - \frac{6}{5} = \frac{- 3}{10}$ nên $x = \frac{3}{2}$