$\left(3x-5y-10z\right)\left(3x-5y-10z\right)$

$\frac{x^6-4x^3+4}{x^3-4x^2}$

$4 x ^ { 2 } - 8 x ^ { 2 } - 6 x ^ { 2 } + 2 x ^ { 2 } - 6 x + 10$

$\frac{a^2b}{5}-\frac{2ab^2}{3}+\frac{3ab^2}{2}-\frac{6a^2b}{6}$

$2-2-4\cdot6+2$

$\frac{d^2}{dx^2}\left(x^2+5\right)^2$

$\lim_{x\to0}\left(\frac{1-cosx\sqrt{cos2x}}{tan^2x}\right)^{\frac{1}{x^2}}$