原式=3+(3-2√3+1)-2+4(√3-1)/(3-1)=3+4-2√3-2+2√3-2=3.
解：v27 +(v3 -1)^2 -(1/2)^(-1) +4/(v3 +1) =3+(3-2v3 +1) -2 +4(v3 -1)/(v3 +1)(v3-1) =3+(4-2v3)-2 +(4v3 -4)/2 = 5-2v3 +2v3-2 =3
