What is the positive solution to x^2+9x-22=0

1 answer

To solve the quadratic equation \( x^2 + 9x - 22 = 0 \), we can use the quadratic formula:

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

In this equation, the coefficients are:

  • \( a = 1 \)
  • \( b = 9 \)
  • \( c = -22 \)

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

\[ b^2 - 4ac = 9^2 - 4(1)(-22) = 81 + 88 = 169 \]

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

\[ x = \frac{-9 \pm \sqrt{169}}{2 \cdot 1} = \frac{-9 \pm 13}{2} \]

Now we compute the two potential solutions:

  1. Using the positive sign: \[ x = \frac{-9 + 13}{2} = \frac{4}{2} = 2 \]

  2. Using the negative sign: \[ x = \frac{-9 - 13}{2} = \frac{-22}{2} = -11 \]

The positive solution is:

\[ \boxed{2} \]