Difference between revisions of "1957 AHSME Problems/Problem 2"

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== Problem ==
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In the equation <math>2x^2 - hx + 2k = 0</math>, the sum of the roots is <math>4</math> and the product of the roots is <math>-3</math>.  
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Then <math>h</math> and <math>k</math> have the values, respectively:
  
PROOF:
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<math>\textbf{(A)}\ 8\text{ and }{-6} \qquad
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\textbf{(B)}\ 4\text{ and }{-3}\qquad
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\textbf{(C)}\ {-3}\text{ and }4\qquad
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\textbf{(D)}\ {-3}\text{ and }8\qquad
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\textbf{(E)}\ 8\text{ and }{-3}  </math> 
  
I am awesome. I never lie. Therefore, I am awesome.
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== Solution ==
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Let the roots of the given equation be <math>r</math> and <math>s</math>. Then, by [[Vieta's Formulas]], we have the following:
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\begin{align*}
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\frac{h}{2} = r+s = 4 &\rightarrow h = 8 \\
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\frac{2k}{2} = rs = -3 &\rightarrow k = -3 \\
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\end{align*}
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Thus, our answer is <math>\boxed{\textbf{(E) } 8 \text{ and } -3}</math>.
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== See also ==
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{{AHSME 50p box|year=1957|num-b=1|num-a=3}}
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{{MAA Notice}}
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[[Category:AHSME]][[Category:AHSME Problems]]
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[[Category:Introductory Algebra Problems]]

Latest revision as of 10:06, 24 July 2024

Problem

In the equation $2x^2 - hx + 2k = 0$, the sum of the roots is $4$ and the product of the roots is $-3$. Then $h$ and $k$ have the values, respectively:

$\textbf{(A)}\ 8\text{ and }{-6} \qquad  \textbf{(B)}\ 4\text{ and }{-3}\qquad  \textbf{(C)}\ {-3}\text{ and }4\qquad \textbf{(D)}\ {-3}\text{ and }8\qquad \textbf{(E)}\ 8\text{ and }{-3}$

Solution

Let the roots of the given equation be $r$ and $s$. Then, by Vieta's Formulas, we have the following: \begin{align*} \frac{h}{2} = r+s = 4 &\rightarrow h = 8 \\ \frac{2k}{2} = rs = -3 &\rightarrow k = -3 \\ \end{align*}

Thus, our answer is $\boxed{\textbf{(E) } 8 \text{ and } -3}$.

See also

1957 AHSC (ProblemsAnswer KeyResources)
Preceded by
Problem 1
Followed by
Problem 3
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All AHSME Problems and Solutions

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