SOLUTION: can anyone please help with this, 1/5+n=2n-4/5

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Question 31925This question is from textbook pre-algebra
: can anyone please help with this, 1/5+n=2n-4/5 This question is from textbook pre-algebra

Answer by Fermat(136) About Me  (Show Source):
You can put this solution on YOUR website!
Could you use brackets when you post a question, thanks.
I'm not usure if your expression is,
1) (1/5) + n = 2n - (4/5)
2) 1/(5+n) = (2n-4)/5
3) (1/5) + n = (2n-4)/5
4) 1/(5+n) = 2n - (4/5)
If it's 1), then
(1/5) + n = 2n - (4/5)
(1/5) + (4/5) = 2n - n
5/5 = n
n = 1
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If it's 2),
1/(5+n) = (2n-4)/5
cross-multiply - i.e. multiply the numerator of the lhs by denominator of the rhs and multiply the numerator of the rhs by the denominator of the lhs. This gives,
1*(5) = (2n-4)*(5+n)
5 = 10n + 2nē - 20 - 4n
2nē + 6n - 25 = 0
using the quadratic formula, x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+, we get
n+=+%28-6+%2B-+sqrt%28+6%5E2-4%2A2%2A%28-25%29+%29%29%2F%282%2A2%29+
n+=+%28-6+%2B-+sqrt%28+36%2B200+%29%29%2F%284%29+
n+=+%28-6+%2B-+15.3623%29%2F%284%29+
n = 2.3406, n = -5.3406
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If it's 3) or 4), could you get the answer to those ?