$15,2\:+\:7$

$\left(4x+3y+2\right)\left(x+5y\right)$

$x^2-2x-2<0$

$\int\frac{x^5}{\sqrt{x^6+7}}dx$

$\lim\:_{x\to\:\infty\:}\left(\sqrt{9x^2+2x}-\sqrt{9x^2-x}\right)$

$\int\frac{1}{\left(x+3\right)\left(x-1\right)\left(x+4\right)}dx$

$\int\frac{\left(3-e^{5x}\right)e^{5x}}{1+e^{5x}}dx$