4分之1+28分之1+70分之1+130分之1=多少? 急哦.麻煩你了. 要簡算的.

4分之1+28分之1+70分之1+130分之1=多少? 急哦.麻煩你了. 要簡算的.


4分之1+28分之1+70分之1+130分之1
=1/3×(1-1/4+1/4-1/7+1/7-1/10+1/10-1/13)
=1/3×12/13
=4/13



簡便算灋2772÷28+31535÷35=


想必是不能用電腦吧?
28 x 100 = 2800 - 28 = 2772 ---->99
31500 + 35 = 31500/35 +35/35 ---->900 +1
99 + 900 +1 = 1000!



巧算2772/28+34965/35
suan shi


2772/28+34965/35
=(2800-28)/28+(35000-35)/35
=100-1+1000-1
=1100-2
=1098



2772÷28+34965÷35.


2772÷28+34965÷35,=99+999,=(100-1)+(1000-1),=1100-2,=1098.