(1) (
1
3 xy ) 2 •(-12 x 2 y 2 )÷(-
4
3 x 3 y)
=
1
9 x 2y 2•12x 2y 2÷
4
3 x 3y
=xy 3;
(2)(x+2) 2-(x+1)(x-1)
=x 2+4x+4-x 2+1
=4x+5;
(3) (-
1
2 ) -2 ×1 0 -1 -(-
1
2 ) 0
=4×
1
10 -1
=-
3
5 ;
(4) (
3
4 a 4 b 7 +
1
2 a 3 b 8 -
1
4 a 2 b 6 )÷(-
1
2 a b 3 ) 2
= (
3
4 a 4 b 7 +
1
2 a 3 b 8 -
1
4 a 2 b 6 )÷
1
4 a 2 b 6
=3a 2b+2ab 2-1.