$\left(\frac{e^x}{e^x+e^y}\cdot\frac{e^y}{e^x+e^y}\right)$

$-a-5^a$

$-\left(-\left(3-5+6\right)-3+6-\left(-2\right)\right)-6+\left(-3\right)$

$4\cos x\sin^3x+4\sin x\cos^3x$

$\int_{\frac{-\pi}{3}}^{\frac{\pi}{3}}\left(sec^2\left(x\right)\right)dx$

$14-\left(-48\right)+\left(-112\right)+8$

$\int\frac{1}{\left(x+a\right)\left(x-a\right)}dx$