Ответ:

Преобразуем данные выражения, используя свойства степеней.

  1. $$x^{-10} \cdot x^{7} = x^{-10+7} = x^{-3} = \frac{1}{x^3}$$
  2. $$x^{8} \cdot x^{-6} = x^{8+(-6)} = x^{8-6} = x^{2}$$
  3. $$x^{-10} \cdot x^{15} \cdot x^{-8} = x^{-10+15-8} = x^{5-8} = x^{-3} = \frac{1}{x^3}$$
  4. $$x^{-2} \cdot x^{7} = x^{-2+7} = x^{5}$$
  5. $$x^{-5} : x^{-12} = x^{-5 - (-12)} = x^{-5 + 12} = x^{7}$$
  6. $$x^{16} \cdot x^{-25} : x^{12} = x^{16-25-12} = x^{-9-12} = x^{-21} = \frac{1}{x^{21}}$$
  7. $$(x^5)^{-7} = x^{5 \cdot (-7)} = x^{-35} = \frac{1}{x^{35}}$$
  8. $$(x^2)^{-8} \cdot (x^{-7})^{-4} : (x^{-3})^{9} = x^{-16} \cdot x^{28} : x^{-27} = x^{-16+28-(-27)} = x^{12+27} = x^{39}$$
  9. $$(x^4y^6z^{-5})^{-9} = x^{4 \cdot (-9)}y^{6 \cdot (-9)}z^{-5 \cdot (-9)} = x^{-36}y^{-54}z^{45} = \frac{z^{45}}{x^{36}y^{54}}$$
  10. $$(x^3y^{-6})^{-5} \cdot (x^{-6}y^8)^{2} = x^{3 \cdot (-5)}y^{-6 \cdot (-5)} \cdot x^{-6 \cdot 2}y^{8 \cdot 2} = x^{-15}y^{30} \cdot x^{-12}y^{16} = x^{-15-12}y^{30+16} = x^{-27}y^{46} = \frac{y^{46}}{x^{27}}$$
  11. $$\frac{x^{13}y^{-5}}{c^{6m^{-12}}} = \frac{x^{13}y^{-5}}{c^{\frac{6}{m^{12}}}} = \frac{x^{13}}{y^{5}c^{\frac{6}{m^{12}}}} $$
  12. $$\left(\frac{x^{-8}}{y^{-5}}\right)^{-4} \cdot \left(\frac{x^{-4}}{y^{8}}\right)^{10} = \frac{x^{(-8) \cdot (-4)}}{y^{(-5) \cdot (-4)}} \cdot \frac{x^{(-4) \cdot 10}}{y^{8 \cdot 10}} = \frac{x^{32}}{y^{20}} \cdot \frac{x^{-40}}{y^{80}} = x^{32-40}y^{-20-80} = x^{-8}y^{-100} = \frac{1}{x^{8}y^{100}}$$