$11r+3-12+2r$

$\frac{\sin\left(-x\right)}{1-\cos\left(-x\right)}$

$\left(2z^{10}\right)\left(-6z^7\right)\left(z^2\right)$

$\frac{\frac{1}{\csc\left(x\right)}}{\cos\left(x\right)-\frac{1}{\sec\left(x\right)^3}}=\frac{1}{sinxcosx}$

$-2a^2b^3+8-14a^2b^3+35$

$_{4+\left(1+50\right)}$

$-72\cdot11$