$4+\left[5-\left(6-9+\left\{7-2\right\}\right)-\left(12-5\right)\right]$

$\cos\left(x\right)^2-\cot\left(x\right)^2$

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

$\left(2d-5\right)\left(a\right)=4b^2-25$

$-\left|-\left(-2\right)\right|$

$64t^2-\frac{4a^2}{8t}-2a$

$\left(\frac{2}{2}a^2\right)\left(-\frac{3}{5}a^5b\right)$