hervorragend
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- Oct 4, 2015
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Solve the equation to determine all possible values of the number
- Thread starter hervorragend
- Start date
D
Deleted member 4993
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Hey guys so here's what I did and I got 0 as one of the numbers. However, on the answer key it also had an 8 as a possible value. I do not know what I did wrong. I need some guidance
You got:
3n = 6\(\displaystyle \sqrt{2n}\)
9n2 = 72n
9n*(n - 8) = 0
Now continue....
hervorragend, this first line of yours is wrong for at least three reasons.
\(\displaystyle \sqrt{9 + 5n} \ = \ 3 + \sqrt{2n} \ \ \ ( \ 3 + \sqrt{2n})\)
The expression in parentheses isn't multiplying anything. It's just floating there.
You i) need the expression immediately after the equals sign inside grouping
symbols, and ii) the expression already in parentheses has to be adjacent to it.
The expression on the left-hand side of the equation has to be squared.
(And it would help to have a step where you show squaring each side)
_____________________________________________________
\(\displaystyle \sqrt{9 + 5n} \ = \ 3 + \sqrt{2n} \)
\(\displaystyle (\sqrt{9 + 5n})^2 \ = \ (3 + \sqrt{2n})^2 \)
\(\displaystyle 9 + 5n \ = \ (3 + \sqrt{2n})(3 + \sqrt{2n}) \)
\(\displaystyle 9 + 5n \ = \ 9 + 6\sqrt{2n} + 2n \)
And continue.
\(\displaystyle \sqrt{9 + 5n} \ = \ 3 + \sqrt{2n} \ \ \ ( \ 3 + \sqrt{2n})\)
The expression in parentheses isn't multiplying anything. It's just floating there.
You i) need the expression immediately after the equals sign inside grouping
symbols, and ii) the expression already in parentheses has to be adjacent to it.
The expression on the left-hand side of the equation has to be squared.
(And it would help to have a step where you show squaring each side)
_____________________________________________________
\(\displaystyle \sqrt{9 + 5n} \ = \ 3 + \sqrt{2n} \)
\(\displaystyle (\sqrt{9 + 5n})^2 \ = \ (3 + \sqrt{2n})^2 \)
\(\displaystyle 9 + 5n \ = \ (3 + \sqrt{2n})(3 + \sqrt{2n}) \)
\(\displaystyle 9 + 5n \ = \ 9 + 6\sqrt{2n} + 2n \)
And continue.