exponents

x^-8   is equal to   1 / x⁸

x² / x⁸  =  1/x⁶    or    x^-6

Use the exponent rule $x^{a} \cdot x^{b} = x^{a+b}$.

$x^2 \cdot x^{-8} = x^{2-8} = x^{-6} = \boxed{\frac{1}{x^6}}$