1.9x9.9x0.19简便法

2025-03-04 05:31:03
推荐回答(1个)
回答1:

1.9x(10-0.1)x0.19
=(19-0.19)x(0.2-0.01)
=0.2x(19-0.19)-0.01x(19-0.19)
=3.8-0.038-0.19+0.0019
=3.5739