(1)原式=4×(-5)-(-21)
=-20+21
=1;
(2)原式=-22×(-
)×25 16
16 25
=4×
×25 16
16 25
=4;
(3)(
?5 6
+5 12
)×(?6)÷2 3
13 2
=(
-10 12
+5 12
)×(-6)×8 12
2 13
=
×(-6)×13 12
2 13
=-6;
(4)32×[(?
)3÷(1 3
)2]×|?5 3
|?(?5)25 3
=9×[-
×1 27
]×9 25
+525 3
=-1+5
=4.