Djamila is looking for conjugate pair solutions to the equation 3x2−5x=−6 . Which of the following options should she choose?(1 point)

Responses

56±5i6
Start Fraction 5 over 6 End Fraction plus or minus Start Fraction 5 i over 6 End Fraction

56±7i6
Start Fraction 5 over 6 End Fraction plus or minus Start Fraction 7 i over 6 End Fraction

56±i47√6
Start Fraction 5 over 6 End Fraction plus or minus Start Fraction i Start Root 47 End Root over 6 End Fraction

−56±i47√6

1 answer

To solve the equation \( 3x^2 - 5x = -6 \), let's first rewrite it in standard form:

\[ 3x^2 - 5x + 6 = 0 \]

Next, we'll apply the quadratic formula, which is given by:

\[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \]

In this equation:

  • \( a = 3 \)
  • \( b = -5 \)
  • \( c = 6 \)

Now, we can calculate the discriminant \( b^2 - 4ac \):

\[ b^2 = (-5)^2 = 25 \] \[ 4ac = 4 \cdot 3 \cdot 6 = 72 \] \[ b^2 - 4ac = 25 - 72 = -47 \]

Since the discriminant is negative (\(-47\)), the solutions will be complex conjugates. Now we can plug our values into the quadratic formula:

\[ x = \frac{-(-5) \pm \sqrt{-47}}{2 \cdot 3} = \frac{5 \pm \sqrt{-47}}{6} \]

This simplifies further:

\[ x = \frac{5 \pm i \sqrt{47}}{6} \]

Based on this, Djamila should choose:

\[ \frac{5}{6} \pm \frac{i \sqrt{47}}{6} \]

From the given options, this matches:

\[ \frac{5}{6} \pm \frac{i \sqrt{47}}{6} \]

So the correct choice is:

\( \frac{5}{6} \pm \frac{i \sqrt{47}}{6} \).