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

$5x^2+5-2x^2+3$

$\lim_{x\to\infty}\left(x\cdot\ln\left(x-4\right)-\ln\left(x+2\right)\right)$

$\lim_{x\to\infty}\left(1+\frac{3}{x}\right)^{\frac{x}{13}}$

$\left(5x\cos\left(y\right)-5x\right)dx-\left(x\sin\left(y\right)\right)dy=0$

$0\le3x^2+4-6x$

$sin\left(2\cdot x\right)-sin\left(4\cdot x\right)$