Вычислите: \((\sqrt{75}-\sqrt{27})^2\)

\(\sqrt{75}=5\sqrt{3}\), \(\sqrt{27}=3\sqrt{3}\).

\[(\sqrt{75}-\sqrt{27})^2=(5\sqrt3-3\sqrt3)^2=(2\sqrt3)^2=12.\]

Ответ: 12.