$\left(8z^4-4n^3\right)\left(8z^4+4n^3\right)$

$\lim_{x\to0}\left(cos\left(4x\right)\right)^{\frac{1}{x^2}}$

$s\left(t\right)=2+\frac{1}{5}\sin\left(2\pi t\right)$

$f\left(x\right)=\frac{1}{\left(x-2\right)\left(x+1\right)}$

$9x^{3}y+3xy^{3}-5x^{3}y+2xy$

$6x^2-6x+1$

$\frac{3}{12}\times4x$