Question

12.9X9.7-12.5X8.7简便运算怎么算？

Answer 1

12.9X9.7减12.5X8.7
=（12.5+0.4）x9.7减12.5X8.7
=12.5x（9.7-8.7）+0.4x9.7
=12.5x1+0.4x（10减0.3）
=12.5+0.4x10减0.4x0.3
=12.5+4减0.12
=16.38

或者是
12.9X9.7减12.5X8.7
=12.9x（8.7+1）减12.5X8.7
=（12.9减12.5）x8.7+12.9x1
=0.4x（9减0.3）+12.9
=0.4x9减0.4x0.3+12.9
=3.6减0.12+12.9
=16.38

Answer 2

12.9×9.7-12.5×8.7
=12.9×（8.7+1）-12.5×8.7
=12.9×8.7+12.9-12.5×8.7
=（12.9×8.7-12.5×8.7）+12.9
=8.7×（12.9-12.5）+12.9
=8.7×0.4+12.9
=3.48+12.9
=16.38

Answer 3

答，12. 9X9. 7一12. 5X（8. 7十1）十12. 5X1=12. 9一12. 5）X9. 7十12. 5=0. 4×9. 7十12. 5=3. 84十12. 5=16. 34

Answer 4

这题不会有简便计算方法吧
具体计算过程如下所示
12.9×9.7-12.5×8.7
=（13-0.1）×（10-0.3）-（12+0.5）×8.7
=130-3.9-1+0.03-12×8.7-0.5×8.7
=125.13-104.4-4.35
=20.73-4.35
=16.38