$-x^2-12x^2-3x^2+15x^2$

$\lim_{x\to0}\left(\frac{3x}{\left(3t-2\right)^2-4}\right)$

$\int_{-40}^{\infty}\frac{-49\cos\left(x\right)}{20}dx$

$-8g+7g+1-9$

$\left(3x^5+4\right)\left(3x^5-4\right)$

$\sin\left(2x\right)\cos\left(x\right)-\sin\left(x\right)=\cos\left(2x\right)\sin\left(x\right)$

$\int_{-\infty}^{-3}\left(\frac{32}{x^2-4}\right)dx$