(2)9^? =x，∴x=3
(3)-2≤3x+4≤2
-6≤3x≤-2
-2≤x≤-2/3。
3 (1) Original formula = 1/4× 16? +log? 4+ 1/3×3+2× 1/2- 1
= 1/4×8+2+ 1+ 1- 1
=2+2+ 1+ 1- 1
=5.