x:( - 3/5) = 1/1/4

Lời giải:

 \[x:\left( { - \frac{3}{5}} \right) = 1\frac{1}{4}\]

\[x:\left( { - \frac{3}{5}} \right) = \frac{5}{4}\]

\[x = \frac{5}{4}.\left( { - \frac{3}{5}} \right)\]

\[x = \frac{{ - 3}}{4}\].

Vậy \[x = \frac{{ - 3}}{4}\].