888. Вычислите: 1) (√6)²; 2) (−√21)²; 3) (3√2)²; 4) (−4√5)²; 5) (−√6/3)²; 6) (1/4√26)².

1. \((\sqrt{6})^2=6\).
2. \((-\sqrt{21})^2=21\).
3. \((3\sqrt{2})^2=3^2\cdot2=18\).
4. \((-4\sqrt{5})^2=(-4)^2\cdot5=80\).
5. \(\left(-\frac{\sqrt{6}}{3}\right)^2=\frac{6}{9}=\frac{2}{3}\).
6. \(\left(\frac{1}{4}\sqrt{26}\right)^2=\frac{26}{16}=\frac{13}{8}\).

Ответ: 1) 6; 2) 21; 3) 18; 4) 80; 5) \(\frac{2}{3}\); 6) \(\frac{13}{8}\).