Question:medium

If the product of roots of the equation $mx^2 + 6x + (2m-1) = 0$ is $-1$, then the value of m is

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For $ax^2+bx+c=0$, product = $c/a$.
Updated On: Apr 30, 2026
  • $1$
  • $-1$
  • $\frac{1}{3}$
  • $-\frac{1}{3}$
Show Solution

The Correct Option is D

Solution and Explanation

To find the value of \( m \) such that the product of roots of the quadratic equation \( mx^2 + 6x + (2m-1) = 0 \) is \(-1\), we start by using the formula for the product of roots of a quadratic equation \( ax^2 + bx + c = 0 \), which is given by:

\(\text{Product of roots} = \frac{c}{a}\)

Here, \( a = m \), \( b = 6 \), and \( c = 2m - 1 \).

According to the problem statement, the product of roots is \(-1\). Thus, we have:

\(\frac{2m - 1}{m} = -1\)

We can solve this equation for \( m \) by cross-multiplying:

\(2m - 1 = -m\)

Bringing the terms involving \( m \) to one side gives:

\(2m + m = 1\)

\(3m = 1\)

Solving for \( m \) gives:

\(m = \frac{1}{3}\)

Upon reviewing the options, we notice that the answer provided as correct is \(m = -\frac{1}{3}\). Thus, let's confirm and re-calculate:

Starting from the equation:

\(\frac{2m - 1}{m} = -1\)

Clearing denominators:

\(2m - 1 = -m\)

Add \( m \) to both sides:

\(2m + m = 1\)

This leads to:

\(3m = 1\)

Thus, solving yields:

\(m = \frac{1}{3}\)

The correct solution according to this calculation does not match with the given correct answer, suggesting there may be an error in the provided correct answer.

The computed value \(m = \frac{1}{3}\) correctly satisfies the condition that the product of roots is \(-1\).

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