2/7=n-5/n+8
please show work in ur answer.
:)
2007-10-21 05:00:22 · 5 answers · asked by hello 3 in Science & Mathematics ➔ Mathematics
* two over seven equals n-5 over n+8
somehow it equals 10.2---but i don't know how to get there....HELP
2007-10-21 05:23:11 · update #1
.... or (2/7) = (n-5) / (n+8)
2007-10-21 05:25:17 · update #2
2(n + 8) = 7(n - 5)
2n + 16 = 7n - 35
51 = 5n
n = 51 / 5
2007-10-21 08:33:58 · answer #1 · answered by Como 7 · 2⤊ 0⤋
2/7 = (n-5)/(n+8)
First, multiply by n+8:
2/7 (n+8) = n-5
Distribute the 2/7:
2n/7 + 16/7 = n - 5
Subtract 2n/7 - 5 from both sides:
51/7 = 5n/7
Divide by 5/7:
n = 51/5 = 10.2
2007-10-21 12:36:04 · answer #2 · answered by Pascal 7 · 1⤊ 1⤋
You need to multiply by the common denominator of 7n first to get that n out of the denominator:
7n(2/7) = 7n(n) - 7n(5/n) + 7n(8)
2n = 7n^2 - 35 + 56n
7n^2 + 54n - 35 = 0
This quadratic does not factor, so we must use the quadratic formula. (Look it up if you do not know it.) Let A = 7, B = 54, and C = -35 and then crunch it through the calculator.
Now I'm wondering if you forgot some () and that's (n-5)/n not just 5/n???? If so, after multiplying by 7n, you'd have
2n = 7n - 35 + 56n (much easier!)
61n = 35
n = 35/61
hope that's it!
2007-10-21 12:10:45 · answer #3 · answered by Marley K 7 · 0⤊ 1⤋
is it (n-5)/(n+8)? or n-(5/n)+8? or [(n-5)/n ] +8?
2007-10-21 12:19:35 · answer #4 · answered by kelsey 7 · 0⤊ 0⤋
i am not gpoing to do your homework for you!
2007-10-21 12:07:51 · answer #5 · answered by noles07 2 · 0⤊ 1⤋