$$\left(7a^2c+2\right)^2$$

$$\lim_{x\to9}\left(\frac{\sqrt{x}-6}{x-9}\right)$$

$$3y^{\frac{1}{\:3}}+c=x+c$$

$$\left(k+5\right)\left(k-5\right)$$

$$4<2x-3$$

$$x-8>0$$

$$\lim_{x\to0}\left(\frac{\sqrt{2x+1}}{\sqrt{4x+1}}\right)$$