$\lim\:_{x\to\:\:0}\left(\frac{\sin\:\left(x\right)-x\cos\:\left(x\right)}{x\sin\:\left(x\right)}\right)$

$-12xy^2z^7-12z^4$

$4x^2+28x+45=0$

$\int\left(2x-3\right)\cdot\left(x-1\right)^{\frac{1}{4}}dx$

$\lim_{x\to-3}\frac{\left(3-\left|x\right|\right)}{\left(3+x\right)}$

$4sen^2x-9\cos^2x=0$

$\int_0^{x^2}\left(3x^{\left(3y\right)}\cdot\:ln\left(y\right)\right)dy$