$\frac{{\left(-0,5\right)}^{12}}{{\left(-0,5\right)}^6}\cdot \frac{-0,5}{{\left(-0,5\right)}^3\cdot {\left(-0,5\right)}^2}={\left(-0,5\right)}^{12-6}\cdot {\left(-0,5\right)}^{1-\left(3+2\right)}={\left(-0,5\right)}^{6-4}={\left(-0,5\right)}^2=0,25$