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Math Help - Solve for x

  1. #1
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    Solve for x

    21x^2 - 83x + 34 = 0

    i know i will get two values of ex by factorization. but i am not being able to middle term factorize it.
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  2. #2
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    Try the quadratic formula.
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  3. #3
    Senior Member eumyang's Avatar
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    Quote Originally Posted by saha.subham View Post
    21x^2 - 83x + 34 = 0

    i know i will get two values of ex by factorization. but i am not being able to middle term factorize it.
    It's not factorable. For it to be factorable over the integers the discriminant would need to be a perfect square.
    \begin{aligned}<br />
b^2 - 4ac &= (-83)^2 - 4(21)34 \\<br />
&= 6889 - 2856 \\<br />
&= 4033<br />
\end{aligned}
    ... and 4033 is not a perfect square.
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  4. #4
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    Relatively few quadratics can be factored with integer coefficients. "Complete the square" or use the quadratic formula instead.
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  5. #5
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    use quadratic formula

    if ax^2+bx+c=0
    then x=\frac{-b\pm \sqrt{(b^2-4ac)}}{2a}

    -- hope it'll help --
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