$\left(4\cdot2\right)+\left(2\cdot5\right)-\left(6\cdot3\right)$

$\:-\:\left[\:4\:-\:\left(\:2\:\right)\left(\:6\:\right)\:\right]\:-\:4\:\left(\:8\:\right)$

$-1+1-9$

$\int\frac{6x^2+3x+7}{\left(x\:-1\right)\left(x^2+2x+5\right)}dx$

$-3\sin\left(x\right)-1$

$\left(9.3-6.6\right)$

$\int_{\frac{7\pi}{12}}^{\frac{3\pi}{4}}\left(\csc\left(2x\right)\cot\left(2x\right)\right)dx$