$2x^2y-6xy^2-8x^2y$

$\left(15x^2y-7xy^2+13y^3\right)-\left(5x^2y-14xy^2+26y^3\right)$

$\sqrt[119]{42^3.115^5.245^7.207^9.154^{11}.104^{13}.32^{16}}$

$y=\frac{\left(11+y\right)}{\left(11-y\right)}$

$\:18x+24$

$\frac{2x+4}{x^2+4x+3}$

$\lim\:_{x\to\:\frac{\pi\:}{2}}\left(\frac{-tan\left(x-\frac{\pi\:}{2}\right)}{x-\frac{\pi\:}{2}}\right)$