$\left|\left(a+2b\right)+\left(5c+2\right)\right|\left|\left(a+2b\right)-\left(5c+2\right)\right|$

$\left(4a+5b^2\right)^2$

$14x^2+8x^3-4x^3-2x^2-3x^2-8x^4$

$-x^3y\::\:7\:xy^3$

$\frac{x^{2}}{3}-\frac{y^{2}}{2}+\frac{z^{2}}{6};x=3;y=4;z=6$

$\lim_{x\to\infty}\left(\frac{9-x^2}{\sqrt{12+x}-3}\right)$

$m^2+25+5$