a) $x-\frac{3}{4}=\frac{2}{7}$ suy ra $x=\frac{29}{28}$
b) $-\frac{3}{8}x-0.75=-1\frac{1}{2}$ suy ra x=2
c) $(0.25-x)/\frac{-3}{5}=-\frac{3}{4}$ suy ra $x=-\frac{1}{5}$
d) $\frac{-3}{5}\times (4x-1.2)=-\frac{12}{25}$ suy ra $4x-\frac{6}{5}=\frac{4}{5}$ nên $x=\frac{1}{2}$