简便方法计算公式 3.8-4.5-5.5+7.2怎么用简便方法做

3.8-4.5-5.5+7.2怎么用简便方法做  

3.8-4.5-5.5+7.2怎么用简便方法做

3.8-4.5-5.5+7.2
=3.8+7.2-（4.5+5.5）
=11-10
=1

6.2*4.5*3.8用简便方法怎么做

6.2*4.5*3.8
=(5+1.2)*(5-1.2)*4.5
=(25-1.2²)*4.5
=25*4.5-1.44*4.5
=25*(4+0.5)-1.44*(5-0.5)
=100+12.5-7.2+0.72
=113.22-7.2
=106.02

3.8乘2.9加21乘3.8减3.8怎么用简便方法

3.8*2.9+21*3.8-3.8=(2.9+21-1)*3.8
=22.9*3.8
=87.02

8.23+4.5—8.23+4.5（用简便方法,怎么用?)

8.23+4.5—8.23+4.5
=8.23—8.23+4.5+4.5
=0+9
=9

0.65×7.2÷0.65×2.8的简便方法怎么用?

0.65×7.2÷0.65×2.8
=0.65÷0.65x7.2x2.8
=1x7.2x2.8
=20.16

7.2×7.5怎么用简便方法计算

7.2×7.5
=（4×1.8）×7.5
=（4×7.5）×1.8
=30×1.8
=54

3.8×0.375＋3.8÷8＋0.5÷0.26 怎么用简便的方法做

3.8×0.375＋3.8÷8＋0.5÷0.26
=3.8*(3/8)+3.8*(1/8)+(1/2)×(50/13)
=3.8*(3/8+1/8)(1/2)×(50/13)
=(1/2)*(3.8+50/13)
=1.9+25/13
=19/10+25/13
=(247+250)/130
=497/130

3.8×0.64+0.62×6.4怎么用简便方法计

0.38x6.4+0.62x6.4
=6.4x(0.38+0.62)
=6.4
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6.25*0.16 264*0.0625 7.2*6.25怎么用简便方法?

原式
=6.25x0.16+264x0.0625+7.2x6.25
=6.25x0.16+2.64x6.25+7.2x6.25
=6.25x(0.16+2.64+7.2)
=6.25x(2.8+7.2)
=6.25x10
=62.5

15.6-(5.6加4.5)怎么用简便方法

15.6-（5.6+4.5）
=15.6-5.6-4.5
=10-4.5
=5.5