Algebra
# Polynomial Arithmetic

Simplify \[\frac{1}{2} ab \times \left(-a^2b\right). \]

Simplify the following expression:

\[ 16 x^3 \div \left( \frac{4}{3} x^2 \right). \]

Simplify \[a^{-2} b^3 \times a^5 b^{-2} \div \left( a^2 b \right). \]

Simplify \[ \frac{9 a^2 b \times 2 c}{36 a c^2} .\]