是化成最简根式吧
1
2^(-2/3)=1/2^(2/3)=1/³√2²=1/³√4=(³√2)/2
2
﹙3+2√2﹚^(-1/2)
=[(1+√2)²]^(-1/2)
=(1+√2)^(-1)
=1/(√2+1)
=√2-1