$\frac{x+1}{5}=\frac{3x-9}{3}$

$\int_0^3\left(\frac{x^5+2}{x^3}\right)dx$

$\lim_{x\to\infty}\left(\frac{4x^2+9x}{7x^3+8x+5}\right)$

$x^2+2y^2+3z^2=0$

$\frac{2d^{4}g^{-4}h^{-3}}{3d^{2}g^{-3}h^{4}}$

$\frac{d^2u}{dt^2}=sin\left(at\right)\cdot cos\left(x\right)$

$\frac{1}{1+\cos\left(x\right)}+\frac{\cos\left(x\right)}{1-\cos\left(x\right)}=\csc\left(x\right)$