必须要简便运算!2.5×1.25×32 (10+0.1+0.01)×39 6.19×2.05+79.5×0.6190.86+9.9×8.6

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/05 01:55:58
必须要简便运算!2.5×1.25×32 (10+0.1+0.01)×39 6.19×2.05+79.5×0.6190.86+9.9×8.6

必须要简便运算!2.5×1.25×32 (10+0.1+0.01)×39 6.19×2.05+79.5×0.6190.86+9.9×8.6
必须要简便运算!
2.5×1.25×32 (10+0.1+0.01)×39 6.19×2.05+79.5×0.619
0.86+9.9×8.6

必须要简便运算!2.5×1.25×32 (10+0.1+0.01)×39 6.19×2.05+79.5×0.6190.86+9.9×8.6
2.5×1.25×32
=2.5×1.25×4×8
=2.54×8×1.25
=10×10
=100
(10+0.1+0.01)×39
=10×39+0.1×39+0.01×39
=390+3.9+0.39
=394.29
6.19×2.05+79.5×0.619
=6.19×2.05+7.95×6.19
=6.19×(2.05+7.95)
=61.9
0.86+9.9×8.6
=8.6×0.1+9.9×8.6
=8.6×(0.1+9.9)
=86