11、（1）原式=(3/2)*根号2 - (1/4)*根号2 + 根号(9/8)
=(3/2)*根号2 - (1/4)*根号2 + (3/4)*根号2
=(3/2 - 1/4 + 3/4)*根号2
=2根号2
（2）原式=15*根号(1/5) + 4*5*根号5 + (1/3)*根号3 - 5根号3
=3根号5 + 20根号5 - (14/3)*根号3
=23根号5 - (14/3)*根号3
11题1,2小题
11、（1）原式=(3/2)*根号2 - (1/4)*根号2 + 根号(9/8)
=(3/2)*根号2 - (1/4)*根号2 + (3/4)*根号2
=(3/2 - 1/4 + 3/4)*根号2
=2根号2
（2）原式=15*根号(1/5) + 4*5*根号5 + (1/3)*根号3 - 5根号3
=3根号5 + 20根号5 - (14/3)*根号3
=23根号5 - (14/3)*根号3