HOW TO EXPRESS -0.58333333333333..... AND -2.575757575...TO FRACTION?
PLZ LIST THE STEP ,THX
RECURRING DECIMAL循環小數
2007-11-04 8:38 pm
回答 (2)
2007-11-04 9:16 pm
✔ 最佳答案
Let y be -0.5833...10y - y = -5.8333... +0.58333...
9y = -5.25
y= -525/900
y= -7/12
Let y be -2.575757575...
100y - y = -257.5757...+2.575757...
99y = -255
y= -25/11
2007-11-06 19:14:05 補充：
for Q2, y is not equal to -25/11 ( I press the calculator wrongly!)the ans should be y= -55/99 = -85/33SORRY =(
2007-11-04 9:19 pm
Let x = -0.5833333333.... ...(1)
10x = -5.83333333... ...(2)
(2) - (1) = 9x = (-5.83333333...+0.583333333....)
9x = -5.25
900x = -525
x = -525/900
x = -7/12
Similarly, let y = -2.57575757... (1)
100y = -257.57575757... (2)
(2) - (1): 99y = (-257.575757... + 2.575757...)
99y = -255
y = -255/99
y = -85/33
10x = -5.83333333... ...(2)
(2) - (1) = 9x = (-5.83333333...+0.583333333....)
9x = -5.25
900x = -525
x = -525/900
x = -7/12
Similarly, let y = -2.57575757... (1)
100y = -257.57575757... (2)
(2) - (1): 99y = (-257.575757... + 2.575757...)
99y = -255
y = -255/99
y = -85/33
收錄日期: 2021-04-13 18:12:16
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20071104000051KK01607