Question

2.1×2.2+1.3X4.2减9.6x0.9用简便方法？

Answer 1

.......2.1x2.2+1.3x4.2-9.6x0.9
....=2.1x2.2+2.6x2.1-9.6x0.9
....=2.1x（2.2+2.6）-4.8x2x0.9
....=2.1x4.8-4.8x1.8
....=4.8x（2.1-1.8）
....=4.8x0.3
....=1.44

Answer 2

2.1×2×1.1十1.3X4.2一9.6×0.9
=4.2×1.1十1.3×4.2一9.6×0.9
=4.2×（1.1十1.3）一2.4×4X0.9
=4.2×2.4一2.4×3.6
=2.4×（4.2-3.6）
=2.4×0.6=1.44

Answer 3

2.1×2.2＋1.3×4.2－9.6×0.9
＝2.1×2.2＋2.6×2.1－9.6×0.9
＝2.1×(2.2＋2.6)－9.6×0.9
＝2.1×4.8－4.8×1.8
＝4.8×(2.1－1.8)
＝4.8×0.3
＝1.44

Answer 4

2.1×2.2+1.3×4.2-9.6×0.9
=2.1×2.2+1.3×2.1×2-9.6×0.9
=2.1×2.2+2.6×2.1-9.6×0.9
=2.1×（2.2+2.6）-9.6×0.9
=2.1×4.8-4.8×2×0.9
=2.1×4.8-4.8×1.8
=4.8×（2.1-1.8）
=4.8×0.3
=（5-0.2）×0.3
=5×0.3-0.2×0.3
=1.5-0.06
=1.44

Answer 5

原式=2.1×2.2+2.6×2.1-9.6×0.9
=2.1×（2.2+2.6）-4.8×1.8
=2.1×4.8-4.8×1.8
=4.8×（2.1-1.8）
=4.8×0.3
=1.44