Tính hợp lý

1/2 +13/19- 4/9+6/19+5/18

50%+1,5: (1-1/3)

5/9-3/5-(-3/9+2/5)

1,25:15/20+(25%-5/6): 14/3

Đáp án:

 `↓`

Giải thích các bước giải:

 `1/2 + (13)/(19) - 4/9 + 6/(19) + 5/(18)`

`= (1/2 - 4/9 + 5/(18))+((13)/(19) + 6/(19))`

`= (9/(18) - 8/(18) + 5/(18)) + 1`

`= 1/3 +1`

`= 1/3 + 3/3`

`= 4/3`

`50% + 1,5 : (1- 1/3)`

`= (50)/(100) + (15)/(10) : (3/3 - 1/3)`

`= 1/2 + 3/2 : 2/3`

`= 1/2 + 3/2 . 3/2`

`= 1/2 + 9/4`

`= 2/4 + 9/4`

`= (11)/4`

`5/9 - 3/5 -(-3/9 + 2/5)`

`= 5/9 + 3/9 - 3/5 - 2/5`

`= 8/9 - 1`

`= 8/9 - 9/9`

`= -1/9`

`1,25: (15)/(20) + (25% - 5/6): (14)/3`

`= (125)/(100) : 3/4 +((25)/(100) - 5/6) . 3/(14)`

`= 5/4 . 4/3 + (1/4 - 5/6) . 3/(14)`

`= 5/3 -7/(12) . 3/(14)`

`= 5/3 - 1/8`

`= (37)/(24)`