2√ 12-√27 +√48

= 1/(2√ 12-√27)+ √48

= 1/(4√3-3√3)+4 √3

=√3/3+4√3

= 13/4√3

6-3/2+2/3

3/(6-√2)+2/√3

=3×(6+√2)/(36-2)+2√3/3

=2√3/3+3√2/34+ 18

√ 32-3 √ 1/2+√ 1/8

1/(√32-3√2)+ 1/√8

= 1/(4√2-3√2)+ 1/2√2

= 1/√2+ 1/2√2

=√2/2+√2/4

=3√2/4

good luck

Jilin Wangqing LLX