(7/11) ^-0.5-3x <(7/11)^x+1.5

( \frac{7}{11} )^{-0,5-3x}\ \textless \ (\frac{7}{11} )^{x+1,5}\\\\-0,5-3x\ \textgreater \ x+1,5\\\\-2\ \textgreater \ 4x\\\\4x\ \textless \ -2\\\\x\ \textless \ -\frac{1}{2}