$\left(x+6\right)^2\:\left(x\:+3\right)\left(x\:+5\right)\:-\:2\left(x+\:1\right)\left(x+\:9\right)$

$9^{x+4}=81^{x-6}$

$g\left(x\right)=\frac{1}{\left(x^3+1\right)}\:series$

$\frac{d^2}{dx^2}x\:\sqrt{\left(x^2\:+36\right)}$

$\int\left(\frac{2}{4+4\tan\left(u\right)^2}.\left(\frac{2\sqrt{3}}{3}\sec\left(u\right)^2\right)\right)du$

$\frac{\left(-1\right)^{39}}{\left(-1\right)^{15}}$