(1)原式=2
2-2
2+2
3
=2
3;
(2)原式=2-2
6+3
=5-2
6;
(3)原式=
2
5+
5
5-
1
3×12
=3-2
=1;
(4)原式=
3+1+3
3-1
=4
3.