$\lim_{x\to\frac{\pi}{2}}\left(-\sin\left(x\right)\right)$

$x3=ay4$

$\int\frac{-x^9+x^4-5}{x^{\frac{3}{4}}}dx$

$\lim_{x\to-2}\left(\frac{x^2-x-6}{x^2+5x+6}\right)$

$\left(2-9\right)-5\left(8-12\right)-7$

$\left(3p^2\right)\cdot\left(7pq^2-6pr\right)$

$12y^2+4y^2+15y^3+33y^3$