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If $2ab = 12$, evaluate $8a^2b^2$.

$\begin{array}{|rcll|} \hline 2ab &=& 12 \quad | \quad : 2 \\ ab &=& \dfrac{12}{2} \\ \mathbf{ab} & \mathbf{=} & \mathbf{6} \\\\ 8a^2b^2 &=& 8 (ab)^2 \quad | \quad \mathbf{ab=6} \\ &=& 8\cdot (6)^2 \\ &=& 8\cdot 36 \\ &=& 288 \\ \hline \end{array}$

$8a^2b^2 = 288$