sqrt(3x+1)-sqrt(x-1)=2
(sqrt(3x+1)-sqrt(x-1))^2=2^2
(3x+1)-2sqrt(3x+1)(x-1)+(x-1))=4
4x-4=2sqrt(3x+1)(x-1)
2x-2=sqrt(3x^2-3x+x-1)
(2x-2)^2=(sqrt(3x^2-3x+x-1))^2
4x^2-8x+4=3x^2-3x+x-1
x^2-6x+5=0
D=b^2-4ac=36-20=16
x1,2=(-b±sqrt(D))/2a
x1,2=(6±4)/2
x1=5
x2=1