7.2×9.9 简算脱式

2024-11-22 08:34:23
推荐回答(5个)
回答(1):

7.2×(10-0.1)
=7.2×10-7.2×0.1
=72-0.72
=71.28

回答(2):

7.2×9.9
=7.2×(10-0.1)
=7.2×10-7.2×0.1
=72-0.72
=71.28
运用的是乘法分配率。

回答(3):

7.2×9.9
=7.2×9.9+0.72-0.72
=7.2×9.9+7.2×0.1-0.72
=7.2×(9.9+0.1)-0.72
=7.2×10-0.72
=72-0.72
=71.28

回答(4):

原式=7.2x(10-0.1)
=7.2x10-7.2x0.1

=72-0.72

=71.28

回答(5):