№ 8. 3) \(\dfrac{40}{(5\sqrt{2})^2}\) и \(\dfrac{27}{(2\sqrt{7})^2}\).

1. \((5\sqrt{2})^2=25\cdot2=50\), поэтому \(\dfrac{40}{50}=\dfrac45\).
2. \((2\sqrt{7})^2=4\cdot7=28\), поэтому \(\dfrac{27}{28}\).

Ответ: \(\dfrac45\) и \(\dfrac{27}{28}\).