3(a+1)^2-(2a-1)
=3a^2+6a+3-2a+1
=3a^2+4a+4
=3*(√3)^2+4*√3+4
=9+4√3+4
=13+4√3先化简,再求值:3(a+1)^2-（2a+1）(2a-1),其中a=根号3 我打错了！3(a+1)^2-(2a+1)(2a-1)=3a^2+6a+3-(4a^2-1)=3a^2+6a+3-4a^2+1=-a^2+6a+4=-(√3)^2+6*√3+4=-3+6√3+4=6√3+1