a. $x + \left ( -\frac{1}{5} \right ) = \frac{-4}{15}$
$x = \frac{-4}{15} + \frac{1}{5}$
$x = \frac{-4}{15} + \frac{3}{15}$
$x = \frac{-1}{15}$
b. $3,7 - x =\frac{7}{10}$
$x = 3,7 - \frac{7}{10}$
$x = \frac{37}{10} -\frac{7}{10}$
$x = \frac{30}{10} = 3$
c. $x . \frac{3}{2} = 2,4$
$x . \frac{3}{2} =\frac{12}{5}$
$x = \frac{12}{5} : \frac{3}{2}$
$x = \frac{12}{5} . \frac{2}{3}$
$x = \frac{8}{5}$
d. $3,2 : x = -\frac{6}{11}$
$\frac{16}{5} : x = -\frac{6}{11}$
$x = \frac{16}{5} : \left ( -\frac{6}{11} \right )$
$x = \frac{16}{5} . \frac{-11}{6}$
$x = \frac{-88}{15}$