$\lim_{w\to-2}\left(\frac{w^2+5w-6}{w^3+8}\right)$

$cos^{\left(4\right)}a-sen^{\left(4\:\right)}a-2cos^{\left(2\right)}a=-1$

$\lim_{x\to\infty}\left(4x.e^{-2}\right)$

$2\log\left(x\right)-\left(3\log\left(y\right)+\log\left(z\right)\right)$

$8^2-5^2$

$5x^2-9x+12$

$\frac{x+x^2}{3-5x^2}$