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

$1^2-3\cdot2-\left(-3\right)$

$\int-\frac{7}{4t\sqrt{16t^2-36}}dt$

$\frac{24}{4}\cdot2+6+2\cdot\left(4+\frac{2^2}{4}-1\right)$

$25\sqrt{9}+38\sqrt{9}$

$2\tan\left(\arccos\frac{x}{6}\right)$

$\int\frac{1}{x}\:+\:2x\:-6\:dx$