請各位幫幫手解答以下問題!plz~
The result of adding 10 to a number and then multiplying it by 7 is equal to the result of multiplying the number by 12 and adding 2 to it.Find the number.
Maths Q's(急用，重賞)
2008-07-28 7:32 pm
回答 (4)
2008-07-31 4:32 am
✔ 最佳答案
設那個數是x7(x+10)=12x+2
7x+70=12x+2
7x+70－7x=12x+2－7x
70=5x+2
70－2=5x+2－2
68=5x
x=13.6
答案一定不是8！
參考: me
2008-08-06 7:47 am
用8依個答案去驗算都唔得la
7(10+8)=12x8+2
70+56=96+2
126≠98
7(10+8)=12x8+2
70+56=96+2
126≠98
2008-07-28 7:41 pm
Let y be the number.
y + 10 x 7 = y x 12 + 2
y + 10 x 7 / 7 = y x 12 + 2 / 7
y + 10 = 12y + 3.5
y + 10 - 3.5 = 12y + 3.5 - 3.5
y + 6.5 - y = 12y - y
6.5 = 11y
6.5 / 11 = 11y / 11
1 / 2 = y
y = 1 / 2
y + 10 x 7 = y x 12 + 2
y + 10 x 7 / 7 = y x 12 + 2 / 7
y + 10 = 12y + 3.5
y + 10 - 3.5 = 12y + 3.5 - 3.5
y + 6.5 - y = 12y - y
6.5 = 11y
6.5 / 11 = 11y / 11
1 / 2 = y
y = 1 / 2
2008-07-28 7:36 pm
Let x be the number
(x+10) * 7 = x *12 +2
7x + 70 = 12x +2
68=5x
x=13.6
(x+10) * 7 = x *12 +2
7x + 70 = 12x +2
68=5x
x=13.6
收錄日期: 2021-04-15 16:53:40
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https://hk.answers.yahoo.com/question/index?qid=20080728000051KK00759