$64x^2+4x^2z+\frac{z^2}{16}$

$-34\cdot75$

$\cos\left(x\right)^2-\cos\left(x\right)^2-\cos\left(x\right)^2$

$\lim_{x\to\sqrt{5}}\left(\frac{x-\:\sqrt{5}}{x^2-5}\right)$

$\left(8x^2+4x-7\right)-\left(2x^2+9x+3\right)$

$0a^3\:-\:2a^3$

$\frac{\frac{2}{5}xy^5z^3}{-\frac{1}{4}z^2}$