$\int\frac{3z+1}{\left(z^2-4\right)^2}dz$

$\lim_{x\to0}\left(\frac{log\left(x+1\right)}{senx}\right)$

$\frac{\sin\left(5x\right)+\sin\left(x\right)}{\cos\left(5x\right)+\cos\left(x\right)}=\frac{\sqrt{3}}{3}$

$2y+11\:para\:y=-4$

$\lim_{x\to0}\left(\frac{\sin\left(14x\right)}{x}\right)$

$12a+3a^2-8a+4a^2$

$6y+\left(y+z\right)$