小學數學 分數加減

1-2 1/2+1 2/3-1 1/2
=1-2 3/6+1 4/6-1 3/6
= -1 3/6+1 4/6-1 3/6
=1/6-1 3/6
= -1 2/6
= -1 1/3

首先將2.3.2 . 找出最小公倍數。

跟住就好簡單啦!!! 我 都係讀小五呀.... 我都好似做過...

係邊本功課有^_^

2 1/2 - 1 2/3 + 1 1/2
= 2 3/6 - 1 4/6 + 1 3/6(通分母)
=15/6-10/6+9/6
=14/6
=7/3(約簡)

=2 1/3 (升)

現在水的總容量比原來的少:
1-2 1/2+1 2/3-1 1/2
=1-2 3/6+1 4/6-1 3/6
= -1 3/6+1 4/6-1 3/6
=1/6-1 3/6
= -1 2/6
= -1 1/3,,

1 - 2 1/2 + 1 2/3 - 1 1/2

X-(X-2 1/2L+1 2/3L-1 1/2L)
=X-(X-3L+1 2/3L)
=X-(X-2 1/3L)

(2 1/2+1 2/3-1 1/2)- 2 1/2
=1/6

我諗應該係多左,唔係少左...

---------------------------------------
希望幫到你la~^^

Let X be the original volume of water.
X-(X-2 1/2L+1 2/3L-1 1/2L)
=X-(X-3L+1 2/3L)
=X-(X-2 1/3L)

一瓶水有幾多升先?

2007-10-05 22:43:29 補充：
如果唔知就係題代數問題"個答案就係:y-2 1/2 1 2/3-1 1/2因為唔知一瓶水有幾多升...所以係唔知少左幾多升...

-2 1/2 + 1 2/3 - 1 1/2

1-(2 1/2)+(1 2/3)-(1 1/2)