$\lim_{x\to0}\left(\frac{ln\left(x+1\right)-a\cdot sen\left(x\right)+sen\left(3x\right)}{x^2}\right)$

$\left(5x^2+4y^4\right)\left(5x^2-4y^4\right)$

$1.15^3$

$a^2+8a+13$

$61.18\cdot1000$

$y'\:=\:9.8\:-\:\frac{v}{10}$

$x\frac{dy}{dx}-y=x\cos\left(x\right)-\sin\left(x\right)$