$2x+y;\:x=7;\:y=10n$

$\sqrt{4x}+\sqrt{9x}$

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

$\frac{d^{13}}{dx^{13}}\left(\sin\left(x\right)\right)$

$f\left(s\right)=\frac{17}{s\left(5s^2-10s+4\right)}$

$xdx=tdt$

$\lim_{x\to0}\left(\frac{\tan\left(x\right)}{x}\right)\left(1\right)$