$\lim_{x\to1}\left(xln\left(x\right)+\left(1-x\right)ln\left(1-x\right)\right)$

$2\left(y^2-9x+\frac{81}{4}\right)$

$x\left(t\right)=10-50t+6t^2$

$\frac{dy}{dx}=y\frac{\left(x-1\right)^2}{y+3}$

$\left(\frac{3.5^6.11^5}{5^4.11^0.\left(-2\right)}\right)^2$

$\frac{-7xy}{-5xz}$

$\lim_{x\to0}\left(\frac{lnx-1}{x-e}\right)$