$3\left(-2\right)-2\left\{5\left[\left(3-5\right)\right]\:\right\}$

$\cot\left(0.643\right)$

$\int\frac{x^5}{\left(36x^2+1\right)^{\frac{3}{2}}}dx$

$4-0.25\cdot10+0.5\cdot5$

$\left(6y^2-5x^3b\right)\cdot\left(36y^4+30bx^3y^2+25x^6b^2\right)$

$y\cdot\left(4+x^2\right)\cdot dy=x\cdot\left(2+y^2\right)\cdot dx$

$\lim_{x\to1}\left(\frac{3x^2-7x+4}{x-1}\right)$