$4x\left(2-x^2-3x^5\right)$

$f\left(x\right)=l\left(ln\:cos\left(2x\right)\:\right)$

$\sec\left(x\right)^2+4$

$-6x\:\left(4-x\right)\:<=\:-4\:\left(x+1\right)$

$\lim_{x\to0}\left(\frac{3n^2+5}{53n\:+\:9}\right)$

$2\sqrt{y}=2\sqrt{x}$

$\int\left(x^{2}+x\right)\sqrt[3]{x+7}dx$