$2xy+6xy2+5xy-7xy2$

$\lim_{x\to2}\left(\frac{2x^2+x-10}{x-2}\right)$

$-2\sin\left(2x\right)=\frac{5}{3}\cos\left(x\right)$

$\lim_{x\to0}\left(\frac{x^2}{\left(\frac{\left(6\cdot\ln\left(3x+1\right)\right)}{3x+1}\right)}\right)$

$-4x^2y\:x\:-2xy^2$

$5\log x+6\log\left(x+7\right)$

$\frac{dy}{dx}+\frac{y}{x}=x^6$