Кто шарит в подобных заданиях ?

[latex] \frac{1}{2^{x-1}}+ \frac{1}{2^{x}}+\frac{1}{2^{x+1}} \ \textless \ 56\\\\ \frac{1}{2^{x}\cdot 1/2}+ \frac{1}{2^{x}}+\frac{1}{2^{x}\cdot 2} \ \textless \ 56\\\\t=2^{x}\ \textgreater \ 0\; ,\; \; \; \frac{2}{t}+\frac{1}{t}+\frac{1}{2t}\ \textless \ 56\\\\ \frac{4+2+1}{2t} \ \textless \ 56 \\\\ \frac{7}{2t} \ \textless \ 56\; \; \to \; \; 7\ \textless \ 112\, t\; \; (t\ \textgreater \ 0)\\\\t\ \textgreater \ \frac{7}{112}\; \; \to \; \; t\ \textgreater \ \frac{1}{16}\; \; \to \; \; 2^{x}\ \textgreater \ 2^{-4}\\\\x\ \textgreater \ -4\\\\x\in (-4,+\infty )[/latex]