Question

Calculati media aritmetica a numerelor :
a) 13, √7 + 6 , -1-√7
b) 10+2√5 , 3-4√5 , 2√5 - 6√7 , 6√7 +11

Answer 1

$m_a=\frac{a+b+c}{3}$

$m_a=\frac{13+\sqrt{7}+6+(-1-\sqrt{7}) }{3}$

$m_a=\frac{13+\sqrt{7} +6-1-\sqrt{7} }{3}$

$m_a=\frac{13+6-1}{3}$

$m_a=\frac{19-1}{3} =\frac{18}{3} \implies m_a=6$

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$m_a=\frac{a+b+c+d}{4}$

$m_a=\frac{10+2\sqrt{5}+3-4\sqrt{5} +2\sqrt{5} -6\sqrt{7}+6\sqrt{7}+11 }{4}$

$m_a=\frac{10+2\sqrt{5}+3-4\sqrt{5}+2\sqrt{5} +11 }{4}$

$m_a=\frac{10+3+11+2\sqrt{5}-4\sqrt{5}+2\sqrt{5} }{4}$

$m_a=\frac{24+2\sqrt{5}-4\sqrt{5} +2\sqrt{5} }{4}$

$m_a=\frac{24+(-2\sqrt{5})+2\sqrt{5} }{4}$

$m_a=\frac{24}{4} \implies m_a=6$