(1)(?
+1 12
+3 4
)×12 1 6
=-
×12+1 12
×12+3 4
×121 6
=-1+9+2
=10;
(2)?
?2÷3×8 9
1 3
=-
-2×8 9
×1 3
1 3
=-
-8 9
2 9
=-
;10 9
(3)?14?(?2)2×(?3)3÷(?1
)21 2
=-1-4×(-27)÷
9 4
=-1-4×(-27)×
4 9
=-1-(-48)
=-1+48
=-47;
(4)2(3x-2x2y)-3(x-3x2y)
=6x-4x2y-3x+9x2y
=3x+5x2y;
(5)3a2-[8a-(4a-7)-2a2]
=3a2-[8a-4a+7-2a2]
=3a2-8a+4a-7+2a2
=5a2-4a-7;
(6)?2(x?
)?3(1?1 2
x)2 3
=-2x+1-3+2x
=-2.