$\lim_{x\to\infty}\left(\frac{x\cdot3^x+12^x}{x\cdot2^x+12^x}\right)$

$sen\left(3x\right)+2\cdot y\cdot cos\left(3x\right)\cdot\frac{dy}{dx}=0$

$\sqrt{\left(9\right)}\left(81\right)$

$\frac{2}{\pi}\int_0^4\left(5x^2+1\right)\cdot\left(cos\left(wx\right)\right)dx$

$\int\frac{6x^4+2x^3-x^2}{2x^3}dx$

$-11a^4b+2a^2b^3+8a^3b^2-4ab^4a^5+b$