发布网友 发布时间:2023-01-02 01:39
共1个回答
热心网友 时间:2023-10-09 00:07
9.9×7.6
=(10-0.1)×7.6
=10×7.6-0.1×7.6
=76-0.76
=75.24
99×0.24
=(100-1)×0.24
=100×0.24-0.24
=24-0.24
=23.76
解:采用分配律,
原式=99x7.6+99x2.4
=99x(7.6+2.4)
=99x10
=990
4.3*1.65+2.35*4.3
=4.3x(1.65+2.35)
=4.3x4
=17.2
9.9*7.6+99*0.24
=9.9x7.6+9.9x2.4
=9.9x(7.6+2.4)
=9.9x10
=99
1.25*5.6
=1.25x8x0.7
=1x0.7
=0.7
5.1*19.96-19.96+19.96*5.9
=19.96x(5.1-1+5.9)
=19.96x10
=199.6
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9.9×7.6+99×0.24
= 9.9×7.6+9.9×2.4
=9.9×(7.6+2.4)
=9.9×10
=99
99乘以任何两位数
思维过程:
两数个位相乘6乘以9=54
其中4为个位,5为百位
两数的十位相乘(7+1)乘以9=72
其中7为最高位,2为十位
所以=7524
加上小数点为75.24
此种方法用于99乘以任何两位数哦
7.6x200.9+4.3x200.9-1.9x200.9
=200.9×﹙7.6﹢4.3-1.9﹚
=200.9×10
=2009
9(a-b)2次方-16(a+b)2次方
=[3﹙a-b﹚﹢4﹙a﹢b﹚][3﹙a-b﹚-4﹙a﹢b﹚]
=[3a-3b﹢4a﹢4b][3a-3b-4a-4b]
=﹙7a﹢b﹚﹙﹣a-7b﹚
9.9×7.6
=(10-0.1)×7.6
=10*7.6-0.1*7.6
=76-0.76
=75.24
=7.6×(0.82+0.04)+2.4×0.82
=7.6×0.82+7.6×0.04+2.4×0.82
=(7.6+2.4)×0.82+7.6×0.04
=10×0.82+0.304
=8.2+0.304
=8.504
7.6+0.24-3.6+1.76
=(7.6-3.6)+(0.24+1.76)
=4+2
=6
2.57x2.4+2.57x7.6=2.57x(2.4+7.6)=2.57x10=25.7