$3ab-4bc-5ab+6bc$

$y=e^{\ln\left(e\right)^{\sin\left(x^2\right)^2}}$

$\lim_{n\to\frac{1}{2}}\left(\frac{1-\cos\left(\pi x\right)}{e^x-\sqrt{e}}\right)$

$\lim_{x\to0}\left(\frac{7x^2}{lnsec\left(x\right)}\right)$

$\left(2^2h^3g^8\right)^2$

$\frac{1}{\csc\left(x\right)-\cot\left(x\right)}-\frac{1}{\csc\left(x\right)+\cot\left(x\right)}$

$3y'\:+xy\:=\:x$