2√3-(√12-1/√2)
=2√3-(2√3-√2/2)
=√2/2
(√2-1)²+(√2-1)(√2+1)
=2-2√2+1+2-1
=3-2√2
x²+4x+1=0
(x+2)²-3=0
(x+2)²=3
x+2=±√3
x=-2±√3