Which of the following is a solution to the quadratic equation 2x^2 - 5x = 6? Assume that the solution has been rounded to the nearest hundredth if applicable.

1 answer

To solve the quadratic equation \( 2x^2 - 5x = 6 \), we first rearrange it into standard form:

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

Next, we can use the quadratic formula, which is given by:

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

In our equation, the coefficients are:

  • \(a = 2\)
  • \(b = -5\)
  • \(c = -6\)

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

\[ b^2 - 4ac = (-5)^2 - 4 \cdot 2 \cdot (-6) = 25 + 48 = 73 \]

Since the discriminant is positive, we will have two real solutions. We can now substitute the values into the quadratic formula:

\[ x = \frac{-(-5) \pm \sqrt{73}}{2 \cdot 2} = \frac{5 \pm \sqrt{73}}{4} \]

Next, we calculate the two possible solutions:

  1. For \(x_1\): \[ x_1 = \frac{5 + \sqrt{73}}{4} \]

Calculating \(\sqrt{73} \approx 8.544\): \[ x_1 \approx \frac{5 + 8.544}{4} = \frac{13.544}{4} \approx 3.386 \]

  1. For \(x_2\): \[ x_2 = \frac{5 - \sqrt{73}}{4} \] Calculating again \(\sqrt{73} \approx 8.544\): \[ x_2 \approx \frac{5 - 8.544}{4} = \frac{-3.544}{4} \approx -0.886 \]

Now, we round the solutions to the nearest hundredth:

  • \(x_1 \approx 3.39\)
  • \(x_2 \approx -0.89\)

Thus, the rounded solutions to the equation \(2x^2 - 5x = 6\) are approximately \(3.39\) and \(-0.89\).