Question

va rog dau coroana si 35 de puncte!​

Answer 1

Răspuns:

sper ca e corect scuze ca e întunecat

Answer 2

$\displaystyle 1.~~a=3\sqrt{15} \cdot \Bigg(\frac{2}{\sqrt{5} }+\sqrt{5} \Bigg)-\sqrt{108}=3\sqrt{15} \cdot \frac{2+\sqrt{5} \cdot \sqrt{5} }{\sqrt{5} }-6\sqrt{3} =\\\\=3\sqrt{15} \cdot \frac{2+5}{\sqrt{5} } -6\sqrt{3} =3\sqrt{15} \cdot \frac{7}{\sqrt{5} }-6\sqrt{3} =3\sqrt{3} \cdot 7-6\sqrt{3} =\\\\=21\sqrt{3} -6\sqrt{3} =15\sqrt{3}$

$2.~~b=\Big(\sqrt{32} -3\sqrt{8}+5\sqrt{18}\Big)\cdot 3\sqrt{2}=\Big(4\sqrt{2} -3 \cdot 2\sqrt{2} +5 \cdot 3\sqrt{2} \Big)\cdot 3\sqrt{2} =\\\\=\Big(4\sqrt{2} -6\sqrt{2} +15\sqrt{2} \Big) \cdot 3\sqrt{2} =13\sqrt{2} \cdot 3\sqrt{2} =39 \cdot 2=78$

$\displaystyle 3.~~c=\Bigg(\frac{7}{6\sqrt{2} } -\frac{5}{3\sqrt{2} }+\frac{\sqrt{18} }{8}\Bigg) \cdot \sqrt{288} =\Bigg(\frac{7}{6\sqrt{2} } -\frac{5}{3\sqrt{2} }+\frac{3\sqrt{2} }{8}\Bigg) \cdot 12\sqrt{2} =\\\\=\frac{7 \cdot 4-5 \cdot 8+3\sqrt{2} \cdot 3\sqrt{2} }{24\sqrt{2} }\cdot 12\sqrt{2} =\frac{28-40+18}{2} =\frac{6}{2} =3$