[tex]\left(\frac{3}{4} \right)^x\leq \left(\frac{4}{3} \right)^{x-1} \\ \\ \left(\frac{3}{4} \right)^x\leq \left(\frac{3}{4} \right)^{1-x} \\ \\ x\geq 1-x \\ \\ x+x\geq 1 \\ \\ 2x\geq 1 \ \ \ \ |:2 \\ \\ x\geq \frac{1}{2} \\ \\ x \in \left[\frac{1}{2},+\infty\right)[/tex]
