這兩題怎麼做?用簡便方法計算(1):57.6×1.6+28.8×36.8-14.4×80 這兩題怎麼做? 用簡便方法計算 (1):57.6×1.6+28.8×36.8-14.4×80 (2):39×37-13×3的4次方

這兩題怎麼做?用簡便方法計算(1):57.6×1.6+28.8×36.8-14.4×80 這兩題怎麼做? 用簡便方法計算 (1):57.6×1.6+28.8×36.8-14.4×80 (2):39×37-13×3的4次方


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



用簡便方法計算:57.6×1.6+28.8×36.8-14.4×80.


57.6×1.6+28.8×36.8-14.4×80=57.6×1.6+28.8×2×18.4-14.4×4×20=57.6×1.6+57.6×18.4-57.6×20=57.6×(1.6+18.4-20)=0



用簡便方法計算:57.6×1.6+28.8×36.8-14.4×80.


57.6×1.6+28.8×36.8-14.4×80=57.6×1.6+28.8×2×18.4-14.4×4×20=57.6×1.6+57.6×18.4-57.6×20=57.6×(1.6+18.4-20)=0