解:因为x=3+2√2
所以1/x=1/(3+2√2)=(3-2√2)/(3+2√2)(3-2√2)=3-2√2
x+1/x=3+2√2+3-2√2=6
x²+1/x²=(1+1/x)²-2=6²-2=34
所以x^2+x^2分之1+3(x+x分之1)-4
=34+3×6-4
=48
x²=(3+2√2)²=17+12√2,
1/x=1/(3+2√2)=(3-2√2),
√x=√(3+2√2)=√(1²+2√2+(√2)²)=1+√2
原式=x²+√x+3x+3/x-4=17+12√2+1+√2+3(3-2√2)-4=23-7√2