Răspuns:
2)
x+√2 = 3x(x+√2)
x+√2 - 3x(x+√2) = 0
(x+√2)(1-3x) = 0
⇒ [tex]\left \{ {{x+\sqrt{2} =0} \atop {1-3x=0}} \right.\\\left \{ {{x=-\sqrt{2}} \atop {3x=1}} \right.\\\left \{ {{x_{1} =-\sqrt{2}} \atop {x_{2} =1/3}} \right.[/tex]
solutia irationala este x₁ = -√2
3)
a = 2k
b = 4k
c = 5k
c = 2a+1 ⇔ 5k = 2·2k+1 ⇔5k-4k = 1 ⇒ k = 1
⇒ a=2, b=4, c =5
