$\int_0^9\left(\frac{x^2}{\sqrt{81-x^2}}\right)dx$

$7+x=-2$

$\left[\left(12x+11\right)\cdot\:\left(8x+9\right)\right]+\left[112x+56x\:2\:+56\:\right]$

$\int\left(3+x^5\right)^55x^4dx$

$\left(x-4\right)\left(x^2+4x+14\right)$

$x ^ { 2 } - 7 x + 14 = 2$

$\int\left(\frac{7}{x^6}\right)dx$