Answer
$\frac{2}{b^{10}}$
Work Step by Step
Start with given expression: $\frac{20b^{10}}{10b^{20}}$
Separate fractions with like terms: $\frac{20}{10}\times\frac{b^{10}}{b^{20}}$
Divide and use quotient rule on fractions: $2b^{-10}$
Use negative exponent rule to simplify: $\frac{2}{b^{10}}$
