$xsen\left(y\right)dx+\left(1+x^2\right)cos\left(y\right)dy=0$

$5-2y+3$

$\lim_{x\to\infty}\left(xtan\left(\frac{6}{x}\right)\right)$

$\frac{-\sin\left(x\right)+\sin\left(x\right)\cos\left(x\right)}{\cos\left(x\right)}=0$

$ln\left(\frac{e^x}{3}\right)$

$\left(4a-5b\right)^2$

$\frac{x^7}{x^4-1}$