Question

Buna! Cum se face asta? Nu imi iese nici cum...... Ex 2. Trebuie sa dea 2

Answer 1

b=√15:√3+1
b=√5x√3:√3+1
b=√5+1

media geometrica=√ab
axb=4/(√5+1)x√5+1=4
media geometrica=√4=2

Answer 2

$a= \frac{4}{ \sqrt{5}+1 }= \frac{4( \sqrt{5} -1)}{( \sqrt{5}+1)( \sqrt{5}-1) }= \frac{4( \sqrt{5}-1) }{5-1}= \sqrt{5}-1 \\ b= \sqrt{15}: \sqrt{3}+1= \sqrt{ \frac{15}{3} }+1= \sqrt{5} +1 \\ M_{g}= \sqrt{ab}= \sqrt{( \sqrt{5}+1)( \sqrt{5}-1) }= \sqrt{5-1} = \sqrt{4}=2$