Question

Calculati va rpg urgent)

√21-√3
------------ *√7=
7-√7

Answer 1

Răspuns:

$\frac{\sqrt{21} -\sqrt{3} }{7-\sqrt{7} } *\sqrt{7} =\frac{\sqrt{7} *\sqrt{3}-\sqrt{3} }{(\sqrt{7})^{2}-\sqrt{7} }*\sqrt{7}=\frac{\sqrt{3}(\sqrt{7}-1) }{\sqrt{7}(\sqrt{7}-1) }*\sqrt{7}=\frac{\sqrt{3} }{\sqrt{7} }*\sqrt{7}=\frac{\sqrt{3} *\sqrt{7} }{\sqrt{7} }=\sqrt{3}$

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