$cos\left(2x+2t\right)+cos\left(2x-2t\right)-cos\left(2x\right)$

$\left(8\right)^2-\left(3x^3\right)$

$\lim_{x\to\infty}\left(ln\left(3x\right)-ln\left(x+5\right)\right)$

$\left(m-6\right)\left(m+3\right)$

$sen^2a\left(1-sen\:a\right)$

$\left|\frac{7}{4}\right|-\left(\frac{3}{2}\cdot\frac{2}{5}\right)^2-\frac{1}{9}$

$\lim_{t\to-1}\left(\left(t^2+1\right)^3\left(t+6\right)^5\right)$