$\left(3x^2+5y\right)\left(3x^2-5y\right)$

$c^4+8c^2+16$

$\frac{\left(\left(x-6\right)^5+\left(x-8\right)^6\right)}{\left(x-6\right)\left(x-8\right)}$

$\int4\left(1+cos\left(t\right)\right)^2dt$

$\frac{d}{dx}y=\sqrt{\frac{x^2-9}{x^2+9}}$

$\lim_{x\to0}\left(\frac{\sqrt{x+3}\sqrt{3}}{x}\right)$

$3x^2y-y^3z^2$