A)2X²-5=0⇒X²=√5/2⇒Xunu=√5/2si Xdoi=-√5/2⇒S={-√5/2, √5/2{
B)(X-1)²-4=0⇒(x-1-2)(x-1+2)=0⇒(x-3)(x+1)=0⇒
x-3=0⇒Xunu=3
x+1=0⇒x=-1
S={-1,3}
C)(6x+1)²-(x+1)²=0
6x²+12x+1-x²-2x-1=0
5x²+10x=0
5x(x+2)=0
Xunu=0
x+2=0
x=-2
S={-2, 0}
D)16x²-1=0
(4x²+1)(4x²-1)=0
4x²+1=0
x²=-1/4⇒ x=√-1/4 nu are solutii
4x²-1=0
x²=1/4
x=1/2 si x=-1/2
S={-1/2, 1/2}
