三個連續數之和減去其最小數的4倍之結果為1。求該三個數。
(要過程)
help me! form1數學
2006-10-27 4:23 am
回答 (5)
2006-10-27 4:34 am
✔ 最佳答案
設最小數為Ｑ。[Ｑ＋(Ｑ＋１)＋(Ｑ＋２)]-４Ｑ＝１
Ｑ＋Ｑ＋１＋(Ｑ＋２)-４Ｑ＝１
Ｑ＋Ｑ＋１＋Ｑ＋２-４Ｑ＝１
３Ｑ＋１＋２-４Ｑ＝１
３Ｑ-４Ｑ＝１－１－２
-１Ｑ＝-２
-Ｑ＝-２
Ｑ＝２
-Ｑ＝-２
點解變左
Ｑ＝２
因為負負得正
參考: 自己
2006-10-29 12:46 am
let xbe the smallest number
(x+x+1+x+2)-4x=1
3x+3-4x=1
x=2
the three are 2,3and4
Prove :
2+3+4-=9
2*4=-8
9-8=1
2006-10-28 16:47:30 補充：
2*4=-8not -8,is 8
(x+x+1+x+2)-4x=1
3x+3-4x=1
x=2
the three are 2,3and4
Prove :
2+3+4-=9
2*4=-8
9-8=1
2006-10-28 16:47:30 補充：
2*4=-8not -8,is 8
2006-10-27 4:31 am
設三個數中, 最小的為x
(x + x+1 + x+2)-4x = 1
(3x+3)-4x = 1
3-x = 1
3-x+x-1 = 1+x-1--------(兩邊加入 x-1)
3-1 = x
x = 2
該三個連續數為 2,3,4
(x + x+1 + x+2)-4x = 1
(3x+3)-4x = 1
3-x = 1
3-x+x-1 = 1+x-1--------(兩邊加入 x-1)
3-1 = x
x = 2
該三個連續數為 2,3,4
2006-10-27 4:27 am
let x be the smallest number
the three numbers are x,(x+1), and (x+2)
x+(x+1)+(x+2)-4x=1
3x+3-4x=1
-x=-2
x=2
so the smallest number is 2
the three numbers are 2, 3 and 4
the three numbers are x,(x+1), and (x+2)
x+(x+1)+(x+2)-4x=1
3x+3-4x=1
-x=-2
x=2
so the smallest number is 2
the three numbers are 2, 3 and 4
收錄日期: 2021-04-23 22:10:38
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