0\\\\20t^2-21\cdot t\cdot \frac{1}{2}+1\leq 0\ \ \ \to \ \ \ 40t^2-21t+2\leq 0\ \ ,\ \ D=121\ ," alt="\left\{\begin{array}{l}5\cdot 2^{2x+2}-21\cdot 2^{x}-1+1\leq 0\\\dfrac{x^2+2x+2}{x^2+2x}+\dfrac{3x+1}{x-1}\leq \dfrac{4x+1}{x}\end{array}\right\\\\\\1)\ \ 5\cdot 2^{2x+2}-21\cdot 2^{x}-1+1\leq 0\ \ ,\\\\5\cdot 2^{2x}\cdot 2^2-21\cdot 2^{x}\cdot \frac{1}{2}+1\leq 0\ \ ,\ \ \ t=2^{x}>0\\\\20t^2-21\cdot t\cdot \frac{1}{2}+1\leq 0\ \ \ \to \ \ \ 40t^2-21t+2\leq 0\ \ ,\ \ D=121\ ," align="absmiddle" class="latex-formula">