Răspuns:
Explicație pas cu pas:
(2×2√5-9√5):5√5=(-5√5):5√5=-1
[tex]\it (2\sqrt{20}-3\sqrt{45}):5\sqrt5 = \dfrac{2\sqrt{20}}{5\sqrt5}-\dfrac{3\sqrt{45}}{5\sqrt5}=\dfrac{2\sqrt4}{5}-\dfrac{3\sqrt9}{5}=\dfrac{4}{5}-\dfrac{9}{5}=-\dfrac{5}{5}=-1[/tex]
