Art of Problem Solving

1950 AHSME Problems/Problem 3: Difference between revisions

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==Solution==
==Solution==
We can divide by 4 to get:
We can divide by 4 to get:
<math> x^{2}-2x+\dfrac{5}{4}=0.</math>
<imath> x^{2}-2x+\dfrac{5}{4}=0.</imath>


Using Vieta's formulas, we find that the roots add to <math>2</math> or <math>\boxed{\textbf{(E)}\ \text{None of these}}</math>.
The Vieta's formula states that in quadratic equation <imath>ax^2+bx+c</imath>, the sum of the roots of the equation is <imath>-\frac{b}{a}</imath>.
Using Vieta's formula, we find that the roots add to <imath>2</imath> or <imath>\boxed{\textbf{(E)}\ \text{None of these}}</imath>.
 
==Solution 2==
We can divide by 4 to get:
<imath> x^{2}-2x+\dfrac{5}{4}=0.</imath>
 
By using quadratic formula you can find the roots are \(x=\frac{8\pm \sqrt{-16}}{8}\) adding the roots together to get 2.
 
or <imath>\boxed{\textbf{(E)}\ \text{None of these}}</imath>.
 
~samma


==See Also==
==See Also==

Latest revision as of 17:42, 9 November 2025

Problem

The sum of the roots of the equation $4x^{2}+5-8x=0$ is equal to:

$\textbf{(A)}\ 8\qquad\textbf{(B)}\ -5\qquad\textbf{(C)}\ -\frac{5}{4}\qquad\textbf{(D)}\ -2\qquad\textbf{(E)}\ \text{None of these}$

Solution

We can divide by 4 to get: $x^{2}-2x+\dfrac{5}{4}=0.$

The Vieta's formula states that in quadratic equation $ax^2+bx+c$, the sum of the roots of the equation is $-\frac{b}{a}$. Using Vieta's formula, we find that the roots add to $2$ or $\boxed{\textbf{(E)}\ \text{None of these}}$.

Solution 2

We can divide by 4 to get: $x^{2}-2x+\dfrac{5}{4}=0.$

By using quadratic formula you can find the roots are \(x=\frac{8\pm \sqrt{-16}}{8}\) adding the roots together to get 2.

or $\boxed{\textbf{(E)}\ \text{None of these}}$.

~samma

See Also

1950 AHSC (ProblemsAnswer KeyResources)
Preceded by
Problem 2
Followed by
Problem 4
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All AHSME Problems and Solutions

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