$\left(12+15\right)\cdot\left(18-11\right)$

$\frac{-9x^3+3x^2+18}{3x+2}$

$\left(b^4\right)\left(b^{-6}\right)$

$39.58+681.39+0.15$

$12+53\cdot2$

$\int\frac{\left(2\right)}{x\sqrt{x^2-4}}dx$

$\lim_{x\to\infty}\:\frac{\left(3\left(x-2\right)\cos\left(3x\right)\right)}{x^2+6x+9}$