I'm SO close to getting the answer, but where do I go from here?

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- Dec 7th 2011, 08:10 PMAlexWilson94Subtraction of binomial fractions?
I'm SO close to getting the answer, but where do I go from here?

http://oi42.tinypic.com/2505ct3.jpg - Dec 7th 2011, 08:17 PMBAdhiRe: Subtraction of binomial fractions?
you cannot take $\displaystyle (a^2+b^2)=(a+b)^2$ (which you've done in 3rd step) just expand and simplify

- Dec 7th 2011, 08:21 PMAlexWilson94Re: Subtraction of binomial fractions?
Are you sure? Why can't I do that? :(

Edit: Either way I get the same answer, which I don't know what to do with.. - Dec 7th 2011, 08:23 PMpickslidesRe: Subtraction of binomial fractions?
Remember $\displaystyle a^2+b^2 \neq (a+b)^2$

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Please avoid attachements if possible - Dec 7th 2011, 08:26 PMBAdhiRe: Subtraction of binomial fractions?
because you, yourself has taken $\displaystyle (x+30)^2=(x^2+60x+30^2)$ at one point (on the fifth line)

so clearly it is not (x^2+30^2) - Dec 7th 2011, 08:27 PMAlexWilson94Re: Subtraction of binomial fractions?
- Dec 7th 2011, 08:28 PMpickslidesRe: Subtraction of binomial fractions?
- Dec 7th 2011, 08:29 PMAlexWilson94Re: Subtraction of binomial fractions?
- Dec 7th 2011, 08:30 PMAlexWilson94Re: Subtraction of binomial fractions?
- Dec 7th 2011, 08:30 PMpickslidesRe: Subtraction of binomial fractions?
- Dec 7th 2011, 08:43 PMAlexWilson94Re: Subtraction of binomial fractions?
So from the 3rd line, I went:

(10x^2 + 9000) - (30x^2 + 1000) = 0

-20x^2 + 6000 = 0

6000 = -20x^2

Then I took the square root of both sides, then divided to square root of 6000 by 20, and wualah. x=3.87 :)

Edit: By the way, how do you get the math symbols? :) - Dec 7th 2011, 08:52 PMpickslidesRe: Subtraction of binomial fractions?
- Dec 7th 2011, 09:03 PMAlexWilson94Re: Subtraction of binomial fractions?