$\left(-11\right)\left\{15+\left(-16\right)\right\}\left\{\left(-14\right)-\left(-11\right)\right\}$

$\lim_{x\to0}\left(\frac{3-3\cos\left(x\right)}{5sinx}\right)$

$\csc\left(x\right)-\sin\left(x\right)=\cot\left(x\right)\cdot$

$9n^2-18n+8$

$-30b^2+20bc-50b+75bc-50c^2+125c-30b+20c-50$

$60-21+14-28+6$

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