Algebra equation challenge!
\[\frac{ 2x }{ 2x^{2}-5x+3} + \frac{ 13x }{ 2x^{2}+x+3} = 6\] If you get stuck I'll show you the next step in solving, but medal to the first who finds the answer!
@amistre64 I'm sure you know how to solve it, but please let others try to guess first lol
x=2??
@AnyTipzWouldHelp Do you know how to solve this equation?
Does x=2??
Should I give you the answer? lol
Yes, I know how to solve it, but I want to see if anyone else can, the first who can gets a medal.
Here's a hint: x equals a negative number.
\[(x=- \sqrt{23})\] ????
Dear AnyTip: It is crucial that you find the Lowest Common Denominator (LCD) of\[\frac{ 2x }{ 2x^{2}-5x+3} + \frac{ 13x }{ 2x^{2}+x+3} = 6\]
before attempting to combine the 2 fractions on the left. Hint: Factor each denominator. Then think about how you might obtain the LCD from the various factors of these 2 denominators.
I know, I'm just leaving it open for the first person to say the right answer, then ill give a medal. But I think they are stumped, so thanks for giving them advice lol
And no Yana, that is not the answer.
The answer, rounded to the nearest hundredth, is x=−3.37
\(\dfrac{ 2x }{ 2x^{2}-5x+3} + \dfrac{ 13x }{ 2x^{2}+x+3} = 6\) \(\dfrac{ 2x }{ (2x - 3)(x - 1)} + \dfrac{ 13x }{ 2x^2 + x+3} = 6\) \((2x - 3)(x - 1)(2x^2 + x+3)\dfrac{ 2x }{ (2x - 3)(x - 1)} +(2x - 3)(x - 1)(2x^2 + x+3) \dfrac{ 13x }{ 2x^2 + x+3} =\) \( =(2x - 3)(x - 1)(2x^2 + x+3) 6\) \(\cancel{(2x - 3)}\cancel{(x - 1)}(2x^2 + x+3)\dfrac{ 2x }{ \cancel{(2x - 3)}\cancel{(x - 1)}}+\) \( +(2x - 3)(x - 1)\cancel{(2x^2 + x+3)} \dfrac{ 13x }{ \cancel{2x^2 + x+3}} =\) \( =(2x - 3)(x - 1)(2x^2 + x+3) 6\) \( (2x^2 + x+3)2x + (2x^2 - 5x + 3)13x = (2x^2 + x + 3)(2x^{2}-5x+3)6 \) \(4x^3 + 2x^2 + 6x + 26x^3 - 65x^2 + 39x =\) \(= (4x^4 - 10x^3 + 6x^2 + 2x^3 - 5x^2 + 3x + 6x^2 - 15x + 9)6\) \(30x^3 - 63x^2 + 45x = 24x^4 - 48x^3 + 42x^2 - 72x + 54\) \(24x^4 - 78x^3 + 105x^2 - 117x + 54 = 0\) \(8x^4 - 26x^3 + 35x^2 - 39x + 18 = 0\) Now let's graph this 4th degree polynomial to get an idea of where to look for real zeros. |dw:1398616931682:dw|
Without graphing, we can see the following. As x becomes less than -10, y will continue to get larger, so there are no zeros there. The same is true for x greater than 10. We found a zero at x = 2. We can also tell that there is a zero at 0 < x < 1.
Now let's look at the Descartes rule of signs: f(x) = 8x^4 - 26x^3 + 35x^2 - 39x + 18 f(-x) = 8x^4 + 26x^3 + 35x^2 + 39x + 18 There are 4 or 2 positive roots. There are no negative roots. Since from the table above we know there is a root at x = 2 and a root at 0 < x < 1, we know there are 2 positive roots. The other two roots must be complex.
Now we use the Rational Zeros Theorem to help us. Since we know we have a root at x = 2, let's use synthetic division to bring the polynomial down by one degree. |dw:1398618530055:dw| Now we need to find a zero between 0 and 1 of 8x^3 - 10x^2 + 15x - 9 = 0
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