$\left|-12\right|-\left|14-12\right|$

$\left(m^2+3\right)\left(m^2+5\right)$

$\int\:\left(\frac{2\left(\arctan\left(\sqrt{x}\right)\right)}{\sqrt{x}\left(1+x\right)}\right)dx$

$\int\left(\frac{5x-3}{\left(x+2\right)\left(x-5\right)}\right)dx$

$130+20\cdot10^2$

$5^{2.4}$

$-2a-b-7a+14b$