Question

数学题解

4.5×8.3-9.5×4.4+1.2×4.5
33.3×14.8+66.6×5.5-99.9×8.6
这两道题可以巧算吗？如果可以，怎么巧算？
急急急急急急

Answer 1

解析：
4.5×8.3-9.5×4.4+1.2×4.5
原式=4.5×（8.3+1.2）-9.5×4.4
=4.5×9.5-9.5×4.4
=9.5×（4.5-4.4）
=0.95
33.3×14.8+66.6×5.5-99.9×8.6
原式=33.3×14.8+33.3×11-33.3×25.8
=33.3×（14.8+11-25.8）
=33.3×0
=0

Answer 2

4.5*8.3-9.5*4.4+1.2*4.5
=4.5*(8.3+1.2)-9.5*4.4
=4.5*9.5-9.5*4.4
=9.5*(4.5-4.4)
=0.95

33.3*14.8+66.6.*5.5-99.9*8.6
=33.3*14.8+33.3*(2*5.5)-33.3*(3*8.6)
=33.3*(14.8+11-25.8)
=33.3*0
=0

Answer 3

4.5×8.3-9.5×4.4+1.2×4.5
=4.5(8.3+1.2)-9.5×4.4
=4.5X9.5-9.5×4.4
=9.5(4.5-4.4)
=...

33.3×14.8+66.6×5.5-99.9×8.6

Answer 4

第一题
先看4.5*8.3+4.5*1.2，那么就是4.5*（8.3+1.2）=4.5*9.5
然后就是4.5*9.5-9.5*4.4=9.5*0.1=0.95

第二题的话
33.3×14.8+66.6×5.5-99.9×8.6
=33.3×14.8+33.3×2×5.5-33.3×3×8.6
=33.3×（14.8+11-25.8）=0

Answer 5

解：（1）4.5×8.3-9.5×4.4+1.2×4.5
=4.5（8.3+1.2）-9.5×4.4……注意到8.3+1.2正好为9.5
=9.5（4.5-4.4）
=0.95
（2）33.3×14.8+66.6×5.5-99.9×8.6
=33.3（14.8+2×5.5-3×8.6）……注意到33.3可提公因式
=33.3（25.8-25.8）
=0

Answer 6

1. =4.5×（8.3+1.2）-9.5×4.4=4.5×9.5-9.5×4.4=9.5×（4.5-4.4）=0.95

2. =33.3×14.8+33.3×2×5.5-33.3×3×8.6=33.3×（14.8+11-25.8）=0