$\lim_{x\to0}\left(\frac{n}{n+1}\right)^n$

$18-3-2\left(7+6-5-2\right)-\left(7-5+2\right)$

$e.y''-10y'+25y=0$

$\tan\left(2x\right)=\tan\left(-y\right)$

$\frac{1}{-\left(y-1\right)^2}dy=-dx$

$\frac{\left(z^4-3z^3+27z^2-4z+4\right)}{\frac{1}{2}z-1}$

$\left(3x^2+2y^2-1\right)^2$