$$\frac{a^6+216b^9}{a^2-6b^3}$$

$$\frac{2^{-2}}{9^{-2}}\cdot\frac{4}{9}$$

$$-1.32+\left(-8.9\right)$$

$$\left[\left(m+n\right)+5\right]\left[\left(m+n\right)-5\right]$$

$$\lim_{x\to0}\left(x^{\left(2x\right)}\right)$$

$$x^2+14xy+49y^2$$

$$xlog\left(x\right)dy=ydx$$