Question

Rezolvati in multimea nr reale ecuatia radical din x+radical din 9-x=3

Answer 1

x+√9-x=3
-x+3=3
-x=3-3=>x=0

Answer 2

x + √(9-x) = 3 

Ridicam la puterea a 2-a ambii membri ai ecuatiei:

[x + √(9-x)]² = 3² ⇒ x+2√x·√(9-x) + 9 - x = 9 ⇒ 2√x·√(9-x) = 0⇒ 

⇒x(9-x) = 0 ⇒ x=0  sau x = 9