Question

初一数学简便运算

1.57.6×1.6+28.8×36.8-14.4×80

2.2.4²×9-1.3²×36

要有过程

Answer 1

=28.8×3.2+28.8×36.8-28.8×40
=28.8×（3.2+36.8-40）
=0

=2.4²×3²-1.3²×6²
=（2.4×3）²-（1.3×6）²
=（2.4×3+1.3×6）×（2.4×3-1.3×6）
=15×(-0.6)
=-9

Answer 2

1、57.6×1.6+28.8×36.8-14.4×80
=14.4×1.6×(4+2×23-50)
=14.4×1.6×0
=0

2.2.4²×9-1.3²×36
=9×（2.4²-1.3²×4）
=9×（5.76-1.69×4）
=9×(-1)
=-9

Answer 3

1. 4*14.4*1.6+2*14.4*36.8-14.4*80
=14.4（4*1.6+2*36.8-80）
=14.4*0
=0
2. 2.4²×9-1.3²×36
=9×（2.4²-1.3²×4）
=9×（5.76-1.69×4）
=9×0
=0

Answer 4

1、57.6×1.6+28.8×36.8-14.4×80
=57.6×1.6+(57.6÷2)×36.8-14.4×4×(80÷4)
=57.6×1.6+57.6×18.4-57.6×20
=0
2、2.42×9-1.32×36
=2.42×32-1.32×62
=7.22-7.82
=(7.2+7.8) ×(7.2-7.8)
=-9

Answer 5

(1) =14.4x4.8+14.4x73.6-14.4x80
=14.4x(4.8+73.6-80)
= -28.8
(2) =(1.2²1.3²)x36
=0.27x36
=9.72