put the sentence into a mathematical "sentence"
1/n+1/12=1/(n-2)
let's mutliply both sides by 12n
12+n=12n/(n-2)
and then both sides by (n-2)
12n-24+n^2-2n=12n
so n^2-2n-24=0
(n-6)(n+4)=0
so n= minus 4 or 6
but we are told it's positive so we can discard the -4
the answer is 6
.
2007-10-11 10:46:05
·
answer #1
·
answered by Anonymous
·
0⤊
0⤋
If you fall for "I can help u for that," you deserve to be scammed. Maybe he will also give you "free" tutoring in English.
Let the unknown number be x. The conditions state that 1/x + 1/12 = 1/(x - 2). Multiply through by 12x*(x - 2) to get 12*(x - 2) + x*(x - 2) = 12x. This simplifies to x^2 - 2x - 24 = 0, or (x - 6)(x + 4) = 0. The solutions are x = 6 or -4, but we are looking for a positive number, so the answer is 6.
2007-10-11 17:00:15
·
answer #2
·
answered by Tony 7
·
0⤊
0⤋
ok so let x be the original number.
reciprocal of original is 1/x.
so the equation would be:
1/x + 1/12 = 1/(x - 2)
multiply by the least common denominator which is 12x(x-2) and u'll get:
12(x-2) + x(x-2) = 12x
12x - 24 + x^2 -2x = 12x
x^2 -2x -24 = 0
(x - 6)(x + 4) = 0
x = 6, -4
since you're looking for a positive number then the original number is 6.
2007-10-11 16:58:46
·
answer #3
·
answered by Anonymous
·
0⤊
0⤋
n = number...
1/n + 1/12 = s
s= 1/ (n-2)
1/n + 1/12 = 1/(n-2)
Then you need to solve this by doing common denominators:
12(n-2) + n(n-2) = 12n
now solve for n:
12n - 24 + n^2 -2n = 12n
n^2 -10n - 12n - 24 =0
n^2 -2n -24 = 0
(n+4) (n-6) =0
n= 6,-4
the number is not negative because of the original stimulation in the question, so the number is 6...
2007-10-11 16:49:14
·
answer #4
·
answered by sayamiam 6
·
1⤊
0⤋
n = positive number
n-2 = two less than the original number
1/n + 1/12 = 1/(n-2)
so n = 6.
2007-10-11 16:49:05
·
answer #5
·
answered by hmata3 3
·
0⤊
1⤋
I think what you mean is
(1/x) + (1/12) = (1/(x -2))
1 + x/12 = x/(x-2)
(x-2) + (x(x-2))/12 = x
12x - 24 + x^2 - x = x
12x -24 + x^2 -2x = 0
x^2 + 10x -24 = 0
(x + 12)(x - 2) = 0
x = -12, x = +2
x is a positive number (from question);
so x = 2
2007-10-11 16:48:45
·
answer #6
·
answered by tinned_tuna 3
·
0⤊
3⤋
i don't know the answer but I know it can't be 2, because 1/(x - 2) would be undefined (division by zero)
2007-10-11 16:52:07
·
answer #7
·
answered by sfroggy5 6
·
0⤊
1⤋