Solve −2x2+3x−1=−2

using the quadratic formula. Round the solution(s) to the nearest hundredths. Enter the smaller solution first.(

1 answer

To solve the equation \(-2x^2 + 3x - 1 = -2\), we first simplify it by moving all terms to one side:

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

This simplifies to:

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

For the quadratic formula, we generally use the form \(ax^2 + bx + c = 0\). Here, we have:

  • \(a = -2\)
  • \(b = 3\)
  • \(c = 1\)

The quadratic formula is given by:

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

First, we calculate the discriminant \(\Delta = b^2 - 4ac\):

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

Now we can use the quadratic formula to find the solutions:

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

This simplifies to:

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

Now we calculate the two possible values for \(x\):

  1. Using the plus sign:

\[ x_1 = \frac{{3 + \sqrt{17}}}{4} \]

  1. Using the minus sign:

\[ x_2 = \frac{{3 - \sqrt{17}}}{4} \]

Next, we will calculate \(\sqrt{17}\):

\(\sqrt{17} \approx 4.123\)

Now substituting this value in:

  1. For \(x_1\):

\[ x_1 = \frac{{3 + 4.123}}{4} \approx \frac{7.123}{4} \approx 1.78075 \]

Rounding to the nearest hundredths gives:

\[ x_1 \approx 1.78 \]

  1. For \(x_2\):

\[ x_2 = \frac{{3 - 4.123}}{4} \approx \frac{-1.123}{4} \approx -0.28075 \]

Rounding to the nearest hundredths gives:

\[ x_2 \approx -0.28 \]

Thus, the final solutions, with the smaller solution first, are:

\[ \boxed{-0.28} \quad \text{and} \quad \boxed{1.78} \]