Solve −2x

2 + 3x − 1 = − 2 using the quadratic formula. Round the solution(s) to the nearest
hundredths. Enter the smaller solution first.

x = or

1 answer

To solve the equation \(-2x^2 + 3x - 1 = -2\), we first rearrange it to standard form:

\[ -2x^2 + 3x - 1 + 2 = 0 \]

This simplifies to:

\[ -2x^2 + 3x + 1 = 0 \]

Next, we will apply the quadratic formula:

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

In our equation, \(a = -2\), \(b = 3\), and \(c = 1\).

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

\[ b^2 - 4ac = 3^2 - 4 \cdot (-2) \cdot 1 = 9 + 8 = 17 \]

Now, we can substitute \(a\), \(b\), and the discriminant into the quadratic formula:

\[ x = \frac{-3 \pm \sqrt{17}}{2 \cdot (-2)} = \frac{-3 \pm \sqrt{17}}{-4} \]

This can be simplified to:

\[ x = \frac{3 \mp \sqrt{17}}{4} \]

Now we calculate both solutions:

  1. For the positive root: \[ x_1 = \frac{3 + \sqrt{17}}{4} \]

    Approximating \(\sqrt{17} \approx 4.123\): \[ x_1 \approx \frac{3 + 4.123}{4} \approx \frac{7.123}{4} \approx 1.78075 \] Rounding to the nearest hundredth, \(x_1 \approx 1.78\).

  2. For the negative root: \[ x_2 = \frac{3 - \sqrt{17}}{4} \]

    Using \(\sqrt{17} \approx 4.123\): \[ x_2 \approx \frac{3 - 4.123}{4} \approx \frac{-1.123}{4} \approx -0.28075 \] Rounding to the nearest hundredth, \(x_2 \approx -0.28\).

So, the final answers rounded to the nearest hundredths are:

\[ x \approx -0.28 \text{ or } 1.78 \]

Thus, the final solutions:

\[ x = -0.28 \text{ or } 1.78 \]