$-3x+y;\:x=2$

$-16+12-4+8-7+31-19-23$

$4-4x^{20}-\frac{1}{9}$

$\frac{dy}{dx}\left(sin\left(x\right)\right)+cos\left(x\right)y=\:2sin\left(x\right)$

$\left(a+2b-c\right)^2\:-\:\left(a+2b+c\right)^2\:$

$\left(-6\right)^2-5$

$\tan\left(u\right)+\cot\left(u\right)=2\csc\left(2u\right)$