$\frac{d^2}{dx^2}\left(7x^2-3x^4y^3+y^7\right)$

$\left(x^2-6x-7\right)\left(3x^2-7x+15\right)$

$\left(\frac{3}{4}x^4+\frac{2}{3}y^3\right)\left(\frac{3}{4}x^4+\frac{2}{3}y^3\right)$

$\int\frac{\left(x\right)}{\sqrt{16+x^2}}dx$

$\frac{x^2-4}{11-2x}$

$-6n+-12$

$\int_{-\infty}^{-7}ln\left|x\right|dx$