1 . daca √3 + √5 < 5√3 ; √5 < 5√3 - √3 ; √5 < 4√3
daca ridicam la patrat 5 < 4²·3 ; 5 < 16·3 ; 5 < 48 adevarat
2. med.geom² = 2√8 ·3√2 = 6√16 = 6·4
⇒ med.geom = √6·√4 = 2√6
3. - 2/3 ·√11 = - √4 √11 / √9 = - √44/√9
4. √ 32 = √16 ·√2 = 4·√2 = 4·1,414 = 5,656
aprox = 5,66