$5a+4\left(3-7a\right)$

$\lim_{x,y\to0,ln2}\left(e^{x-y}\right)$

$\int\frac{1}{\left(x-3\right)\left(x+3\right)}dx$

$\lim_{x\to0}\left(\frac{\sqrt{x+3}-\sqrt{2}}{x+1}\right)$

$\frac{2}{1}+\frac{1}{1}$

$\left(7a+3b\right)\left(7a+8b\right)+\left(a-b\right)\left(a-4b\right)$

$\frac{\sqrt{x+2}}{\sqrt{x+2}+\sqrt{x+1}}$