If 1/x = 3.5. then 1/(x+2) =?
7/9
16/7
7/16
9/7
7/4
What is the correct answer and WHY?
回答 (9)
✔ 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)
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.
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
That means x=1/3.5.
So. 1/(x+2) = 1/((1/3.5)+2) = .4375 = 7/16.
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
1/x = 3.5
x = 1/3.5 =2/7
Thus, 1/(x + 2) = 1/(2/7 + 2) = 7/16
x = 1/3.5 = 2/7, so x + 2 = 14/7 + 2/7 = 16/7, so 1/(x + 2) = 7/16
1/x = 3.5
x = 1/3.5
putting x =1/3.5 in
1/(x+2)
we get
7/16
x = 1 / 3.5 = 2 / 7
1 / (x + 2) = 1 / (2/7 + 2) = 1 / (16/7) = 7/16
收錄日期: 2021-05-01 11:39:21
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