这两题怎么做? 用简便方法计算 (1):57.6×1.6+28.8×36.8-14.4×80这两题怎么做?用简便方法计算(1):57.6×1.6+28.8×36.8-14.4×80(2):39×37-13×3的4次方
问题描述:
这两题怎么做? 用简便方法计算 (1):57.6×1.6+28.8×36.8-14.4×80
这两题怎么做?
用简便方法计算
(1):57.6×1.6+28.8×36.8-14.4×80
(2):39×37-13×3的4次方
答
57.6x1.6+28.8x36.8-14.4x80
=57.6x1.6+28.8x2x18.4-14.4x4x20
=57.6x1.6+57.6x18.4-57.6x20
=57.6x(1.6+18.4-20)
=0
39x37-13x3x3x3x3
=39x37-39x27
=39x(37-27)
=390