Respostas

2014-08-19T13:26:10-03:00
√x-1 = 3-x (Racionalizando)
(√x-1)² = (3-x)²
x - 1 = 9 - 3x - 3x + x²
x - 1 - 9 + 3x + 3x - x² = 0
-x² + 7x - 10 = 0 (-1)
x² - 7x + 10 = 0

Δ = 49 - 40 = 9

x = 7 +- 3
        2
x¹ = 5
x² = 2

Testando as raízes :
x¹ ⇒ √5-1 = 3-5 ⇒ √4 = -2 ⇒ 2 = -2 (Errada)
x² ⇒ √2-1 = 3-2 ⇒ √1 = 1 ⇒ 1 = 1 (Correta) 
1 5 1