Если х=-1, то
Решение будет единственным, т.к.
-1\quad (\frac{1}{3})^{x}<3,(\frac{1}{4})^{x}<4\quad \to \quad (\frac{1}{3})^{x}+(\frac{1}{4})^{x}<7\\\\b)\quad pri\quad x<-1:\quad (\frac{1}{3})^{x}>3,(\frac{1}{4})^{x}>4\quad \to \quad (\frac{1}{3})^{x}+(\frac{1}{4})^{x}>7" alt="a)pri\quad x>-1\quad (\frac{1}{3})^{x}<3,(\frac{1}{4})^{x}<4\quad \to \quad (\frac{1}{3})^{x}+(\frac{1}{4})^{x}<7\\\\b)\quad pri\quad x<-1:\quad (\frac{1}{3})^{x}>3,(\frac{1}{4})^{x}>4\quad \to \quad (\frac{1}{3})^{x}+(\frac{1}{4})^{x}>7" align="absmiddle" class="latex-formula">