Question

Simplify the expression using properties of exponents.

Answer 1

$\dfrac{12a^{-9}b^{-4}}{9a^2b^6}=\dfrac{12:3}{9:3}a^{-9-2}b^{-4-6}=\dfrac{4}{3}a^{-11}b^{-10}\\\\=\boxed{\dfrac{4}{3a^{11}b^{10}}}\to \boxed{B.}\\\\\text{used:}\\\\\dfrac{a^n}{a^m}=a^{n-m}\\\\a^{-n}=\dfrac{1}{a^n}$