(1)原式=-4-(-27)×1-(-1)
=-4+27+1
=24;
(2)原式=-48×
-48×(-1 2
)-48×5 8
-48×(-1 3
)11 16
=-24+30-16
=-10;
(3)原式=-1-
×(2-9)1 6
=-1+
7 6
=
;1 6
(4)原式=x2+2xy+y2-x2+xy-y2
=3xy;
(5)原式=9a2-(7a2-2a-2a2+6a)-3
=9a2-7a2+2a+2a2-6a-3
=4a2-4a-3;
(6)原式=2a2b+6ab2-3a2b+3-2a2b-2
=6ab2-3a2b+1,
当a=-2,b=2时,原式=6×(-2)×22-3×(-2)2×2+1=-48-24+1=-72+1=-71.