a) $\frac{3}{7}$ + x = -1,5
x = -1,5 - $\frac{3}{7}$
x = $\frac{-27}{14}$;
b) $3\frac{1}{5}$ - x = 1,6 + $\frac{7}{10}$
x = $3\frac{1}{5}$ - 1,6 - $\frac{7}{10}$
x = 0,9;
c) x * $\frac{14}{3}$ = 2,5
x = 2,5 * $\frac{3}{14}$
x = $\frac{15}{28}$;
d) x / (- $\frac{3}{5}$) = $1\frac{1}{4}$
x = (- $\frac{3}{5}$) * $1\frac{1}{4}$
x = - 0,75.