第3个回答 2018-02-28
(1)2.64×1.7-2.64×0.7
=2.64×(1.7-0.7)
=2.64×1
=2.64
(2)31.5×1.07-3.15×0.7
=3.15×10.7-3.15×0.7
=3.15×(10.7-0.7)
=3.15×10
=31.5
(3)2.7×5.7-2.7+5.3×2.7
=2.7×(5.7-1+5.3)
=2.7×10
=27
(4)0.625÷0.125×0.8
=(0.625×0.8)×8÷(0.128×8)
=0.5×8÷1
=4
(5)18.6×6.1+3.9×18.6
=18.6×(6.1+3.9)
=18.6×10
=186
(6)1.3579+3.5791+5.7913+7.9135+9.1357
=(1+3+5+7+9)×1.1111
=25×1.1111
=27.7775
(7)52.5x2.9+5.45
=5.25x29+5.25+0.2
=5.25×(29+1)+0.2
=5.25×30+0.2
=157.5+0.3
=157.7
(8)0.92x15+0.08x15
=(0.92+0.08)×15
=1×15
=15
(9)0.72×1.25×2.5
=0.9×(0.8×1.25)×2.5
=0.9×1×2.5
=2.25
(10)400.6x7-2003x0.4
=200.3x14-200.3x4
=200.3×(14-4)
=200.3×10
=2003
第4个回答 2019-02-17
1/6 + 1/2 -1/6 =1/2,
7.5-(2.5+3.8)=1.2,
4/5 - 7/10 =1/10,
2 - 1/6 -1/3 =1.5
0.51÷17=0.03,
32.8+19=51.8,
5.2÷1.3=4,
1.6×0.4= 0.64
4.9×0.7=3.43,
25*4/25*4
7.26-(5.26-1.5)
286+198
314-202
526+301
223-99
6.25+3.85-2.125+3.875
9-2456*21
0.5/11.5-4*2.75
1/2×3/5
3.375+5.75+2.25+6.625
1001-9036÷18
3.8×5.25+14.5
2.1*4.3+5.7*2.1
30×1/3