$$\left(a^2+a-6\right)\left(a^2-6\right)$$

$$\lim_{x\to2}\left(\frac{x^3-8}{\left|x-2\right|\sqrt{x^2+5}}\right)$$

$$20+90+5$$

$$\left(t^4-1\right)^3\left(t^3+1\right)^4$$

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

$$\arcsin\left(\frac{-2}{5.4}\right)$$

$$z=x^2\sin\left(6y\right)$$