\[\boxed{\mathbf{1206}\text{.\ }\text{еуроки}\text{-}\text{ответы}\text{\ }\text{на}\text{\ }\text{пятёрку}}\]
\[\textbf{а)}\ x^{10}\ :x^{12} = x^{10 - 12} = x^{- 2}\]
\[\textbf{б)}\ x^{0}\ :x^{- 5} = x^{0 - ( - 5)} = x^{5}\]
\[\textbf{в)}\ x^{n - 1}\ :x^{- 8} =\]
\[= x^{n - 1 - ( - 8)} = x^{n + 7}\]
\[\textbf{г)}\ x^{6}\ :x^{n + 2} = x^{6 - n - 2} = x^{4 - n}\]