Answer
$2$
Work Step by Step
(i) $a^m \cdot a^n = a^{m+n}$
(ii) $\dfrac{a^m}{a^n}=a^{m-n}$
(iii) $a^{-m} = \dfrac{1}{a^m}, a \ne 0, m \gt0$
(iv) $(a^m)^n=a^{mn}$
Use the applicable rules above to find:
$\require{cancel}=\dfrac{20x^8}{10x^8}
\\=\dfrac{20\cancel{x^8}}{10\cancel{x^8}}
\\=\dfrac{20}{10}
\\=2$
