If 1/x = 3.5. then 1/(x+2) =?

2008-12-21 11:42 am
7/9
16/7
7/16
9/7
7/4

What is the correct answer and WHY?

回答 (9)

2008-12-21 11:46 am
✔ 最佳答案
1/x = 3.5
x=1/3.5
x=2/7

evaluating
1/(x+2)= 1/(2/7+2)
7/16 (answer)
2008-12-21 11:58 am
1st equation: find the value of x:
1/x = 3.5
3.5x = 1
2(3.5x) = 2(1)
7x = 2
x = 2/7

2nd equation: plug x with 2/7:
= 1/(2/7 + 2)
= 1/(2/7 + 14/7)
= 1/(16/7)
= 1(7/16)
= 7/16

Answer: 7/16 or the 3rd choice among the list of 5 choices.
2008-12-21 11:45 am
1/x = 3.5
1 = 3.5x
x = 1/3.5

1/(x + 2)
= 1/(1/3.5 + 2)
= 1/(1/3.5 + 7/3.5)
= 1/(8/3.5)
= 1(3.5/8)
= 3.5/8
= (3.5 * 2)/(8 * 2)
= 7/16
2008-12-21 1:06 pm
That means x=1/3.5.
So. 1/(x+2) = 1/((1/3.5)+2) = .4375 = 7/16.
2008-12-21 12:55 pm
1/x = 3.5 [Change decimal to fraction]
1/x = 7/2 [Cross-multiply]
1 = (7/2)x
x = 1/(7/2)
x = 2/7

1/(x + 2)
1/((2/7) + 2)
1/((2/7) + (14/7))
1/(16/7)
7/16
參考: Equation Calculator: http://algebrahelp.com/calculators/equation/
2008-12-21 12:00 pm
1/x = 3.5
x = 1/3.5 =2/7

Thus, 1/(x + 2) = 1/(2/7 + 2) = 7/16
2008-12-21 11:48 am
x = 1/3.5 = 2/7, so x + 2 = 14/7 + 2/7 = 16/7, so 1/(x + 2) = 7/16
2008-12-21 11:48 am
1/x = 3.5

x = 1/3.5
putting x =1/3.5 in

1/(x+2)
we get
7/16
2008-12-21 4:19 pm
x = 1 / 3.5 = 2 / 7

1 / (x + 2) = 1 / (2/7 + 2) = 1 / (16/7) = 7/16


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