$\frac{d}{dx}xy+x-2y-1=0$

$\left(3x^{a}-5y^{m}\right)\left(5y^{m}+3x^{a}\right)$

$\lim_{x\to1}\left(\frac{\ln\left(x-1\right)}{\ln\left(sin\left(x-1\right)\right)}\right)$

$\int x^3\cdot e^{4x-5}dx$

$25x^4-25y^4$

$\:2e^{-2x}-16e^{-x}$

$\frac{-3\left(-4+\left|-2\right|\right)}{3.2}$