$-\frac{4}{1}$

$56\cdot54$

$\lim_{x\to-\infty}\left(\frac{\sqrt{4x^6+x^2}}{x^3+1}\right)$

$\frac{\cot\left(a\right)+\tan\left(a\right)}{\cot\left(a\right)-\tan\left(a\right)}=\sec\left(2a\right)$

$\left(3-x\right)-\frac{1}{2}\left(x-4\right)\geq\frac{1}{3}\left(2x-3\right)-x$

$-6x+3\le-8x-7$

$\lim_{x\to\frac{1}{4}}\left(\frac{2x^2+x^3}{x}\right)^{\frac{1}{4}}$