$\left(-3\:+\:\frac{7}{n}\right)^2$

$\frac{dy}{dx}-5y^2=-\frac{5}{2}x.y^3$

$y'+y=xe^{-x}+1$

$\lim_{x\to\infty}\left(\frac{\sqrt{x^2+1}}{x+2}\right)$

$3a^2+7a+3$

$\left(e^2^{\infty}+1\right)^{\frac{1}{\infty}}$

$\frac{1+\cos\left(x\right)}{\sin\left(x\right)}+\frac{\sin\left(x\right)}{\cos\left(x\right)}$