(-0.4)×(-0.8)×(-1.25)×2.5
=-(0.4×0.8×1.25×2.5)
=-(0.4×2.5×0.8×1.25)()
=-[(0.4×2.5)×(0.8×1.25)]()
=-(1×1)
=-1.
原式= ×
= ×
=.
⑵计算 时,观察算式的特点,运用分配律可得:
原式=(-36)×-(-36)×+(-36)×-(-36)×
=
(-4)×8×(-2.5)×(-125)
=-4×8×2.5×125
=-4×2.5×8×125()
=-(4×2.5)×(8×125)()
=×