Сравните числа 5*корень из (7/5) и 1/2*корень из (140).

\[5\sqrt{\frac{7}{5}} = \frac{1}{2}\sqrt{140}\]

\[5\sqrt{\frac{7}{5}} = \sqrt{\frac{7 \cdot 25}{5}} = \sqrt{35}\]

\[\frac{1}{2}\sqrt{140} = \sqrt{\frac{140}{4}} = \sqrt{35}\]

\[\sqrt{35} = \sqrt{35}.\]