作业帮72x0.81 10.4如何简便计算
来源：学生作业帮助网 编辑：作业帮 时间：2024/05/01 19:10:20
0.027+9.9x0.27=0.27×0.1+9.9×0.27=0.27×(0.1+9.9)=0.27×10=2.7
7.56+0.12x0.9+0.44=(7.56++0.44)+0.12x(1-0.1)=8+0.12-0.012=8.12-0.012=8.108
72*0.9*0.9+10.4再问：列递式再答：0.8*0.9*0.9*0.9+0.8*13=（0.9*0.9*0.9+13）*0.8=（0.072+13）*0.8再问：不对再答：哦哦0.8*90*0
12.5-12.5×0.2＝12.5×1-12.5×0.2＝12.5×（1-0.2）＝12.5×0.8＝10
2.8×0.5+1.58=1.4+1.58=1.4+1.6-0.02=3-0.02=2.98
再答：如果满意请采纳谢谢
有简便方法,方法如下：根据(x-0.1)^3=x^3-0.3x^2+0.03x-0.001,把x=1代入即得,原式=1-0.3+0.03-0.001=0.729
这个没法简算52.5x0.63+3.7x0.5=33.075+1.85=34.925
1.25x0.25x0.05x64=1.25x0.25x0.05x8×8=1.25x8x0.25x(0.05x8)=10x0.25x0.4=2.5x0.4=1
8.45X0.27+8.45X0.63+0.845=8.45X0.27+8.45X0.63+0.845x1=8.45X0.27+8.45X0.63+8.45x0.1=8.45X（0.27+0.63+0
102x0.35=(100+2)x0.35=100x0.35+2x0.35=35+0.7=35.7
25.25x0.64x4/0.64=25.25x4=25x4+0.25x4=100+1=101
18.5-（0.25+0.75）=18.5-1
0.125x4.8x0.25=0.125×8×（0.25×2）×0.3=1×0.5×0.3=0.15
=0.3×(2.5×0.4)=0.3×1=0.3
0.27+9.9x0.27=0.27+(10-0.1)x0.27=0.27+10x0.27-0.27x0.1=0.27+2.7-0.027=2.943
(99+1)×0.027再答：=2.7
12.5x0.25x3.2=（12.5×0.8）x（0.25x4）=10×1=10