最好是递等式计算谢谢!

题目

最好是递等式计算谢谢!
1）3.7×1.4×0.05
2）2.7×3.7+0.37×73
3）2.3×6.7-9.24
4）1.25×23×1.6
5）16.5×9.9
6）0.64+0.36×0.25
7）3.9×7.8+39×0.12+3.9
8）3.05-2.05×1.4

答案

1）3.7×1.4×0.05
=3.7×0.07
=0.259
2）2.7×3.7+0.37×73
=3.7×（2.7+7.3）
=3.7×10
=37
3）2.3×6.7-9.24
=15.41-9.24
=6.17
4）1.25×23×1.6
=1.25×8×2.3×2
=10×4.6
=46
5）16.5×9.9
=16.5×（10-0.1）
=165-1.65
=163.35
6）0.64+0.36×0.25
=0.64+0.09
=0.73
7）3.9×7.8+39×0.12+3.9
=3.9×（7.8+1.2+1）
=3.9×10
=39
8）3.05-2.05×1.4
=1+2.05-2.05×1.4
=1-2.05×0.4
=1-0.82
=0.18