$\frac{\left(sin\left(-x\right)tan\left(-x\right)\right)}{secx}$

$\left(-2x+3y-4z\right)^{2}$

$\lim_{x\to\pi}\left(\frac{2x^2-6x\pi+4\pi^2}{x^2-\pi^2}\right)$

$\frac{\left(a+b\right)\left(a-b\right)}{a^2-2ab+b^2}$

$\:ln\left(\:cosh\left(4x\right)\:+\:sinh\left(4x\right)\:\right)\:+\:ln\left(\:cosh\left(3x\right)\:-\:sinh\left(3x\right)\:\right)\:$

$-15+5\left(-2\right)$

$\left(\frac{1}{3}-6m\right)-\left(\frac{1}{4}n-8\right)$