$3\cdot\left(0.5\right)^2-2\cdot\left(0.5\right)-1$

$sen\:\frac{\pi}{2\:\:}\:-\:\frac{\pi}{6}$

$m^4-45^2+100$

$2\left(1\right)^3-+4\left(1\right)^2+\left(1\right)+2$

$\left(-b+4\right)\left(-b-7\right)$

$\left(\frac{3}{4}a-2b\right)^2$

$\frac{\sin\left(x\right)}{\cos\left(x\right)-1}=-\cot\left(\frac{x}{2}\right)$