$\pi$ (3-r)(3+r)
You asked:
Evaluate the expression: \(\pi \cdot \left(3 - r\right) \cdot \left(3 + r\right)\)
MathBot Answer:
\[\pi \cdot \left(3 - r\right) \cdot \left(3 + r\right) = \pi \left(3 - r\right) \left(r + 3\right)\]
Expanded
\[\pi \cdot \left(3 - r\right) \cdot \left(3 + r\right) = - r^{2} \pi + 9 \pi\]
Factored
\[\pi \cdot \left(3 - r\right) \cdot \left(3 + r\right) = - \pi \left(r - 3\right) \left(r + 3\right)\]