$\lim_{x\to\infty}\frac{2x^4+x^2+5}{3x^5+x^3-x}$

$a\:-\:\frac{b\cdot c\:-\:c^2\cdot d}{e-c^2}$

$\frac{4x^3+2x^2+1}{4x^3-x}$

$\left(3\sin\left(x\right)-10\right)^2$

$\lim_{x\to0}\left(x^2ln\left(x\right)\right)$

$2x+20\le-30$

$\left(2+x\right)\sin\left(y\right)dx+\cos\left(y\right)dy=0$