$\left(a-b+1\right)^2-\left(1-a-b\right)^2$

$\frac{dy}{dx}=\frac{x^4}{16}$

$\int\left(4x^3\cdot\cos\left(2x^4\right)\right)dx$

$\left(81x^{12}-4\right)$

$\left(2x^a+13\right)\left(2x^a-8\right)$

$\lim_{x\to1}\left(\frac{\log\left(2x-1\right)}{x^2+x-2}\right)$

$4z^2+9-12z$