$3\left(2a\right)\left(3b\right)^2$

$\int\left(\frac{x^2-1}{x^2-16}\right)dx$

$\lim_{x\to0}\left(\frac{\log\left(\sin\left(7x\right)\right)}{\log\left(\sin\left(x\right)\right)}\right)$

$\int_{-5}^5\sqrt{25-x^2}dx$

$-23-\left(2+\left(-3\right)\right)$

$-4x-16$

$2x^3\left(6x+9\right)-4x^2\left(4x-8\right)$