Which are the solutions of x2 = –11x + 4?

StartFraction negative 11 minus StartRoot 137 EndRoot Over 2 EndFraction comma StartFraction negative 11 + StartRoot 137 EndRoot Over 2 EndFraction
StartFraction negative 11 minus StartRoot 125 EndRoot Over 2 EndFraction comma StartFraction negative 11 + StartRoot 125 EndRoot Over 2 EndFraction
StartFraction 11 minus StartRoot 137 EndRoot Over 2 EndFraction comma StartFraction 11 + StartRoot 137 EndRoot Over 2 EndFraction
StartFraction 11 minus StartRoot 125 EndRoot Over 2 EndFraction comma StartFraction 11 + StartRoot 125 EndRoot Over 2 EndFraction

1 answer

To solve the equation \( x^2 = -11x + 4 \), we first rearrange it to standard quadratic form:

\[ x^2 + 11x - 4 = 0 \]

Now we can apply the quadratic formula, which states:

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

In our equation, \( a = 1 \), \( b = 11 \), and \( c = -4 \).

  1. Calculate the discriminant:

\[ b^2 - 4ac = 11^2 - 4(1)(-4) = 121 + 16 = 137 \]

  1. Plugging the values into the quadratic formula gives us:

\[ x = \frac{-11 \pm \sqrt{137}}{2(1)} = \frac{-11 \pm \sqrt{137}}{2} \]

So, the solutions are:

\[ x = \frac{-11 - \sqrt{137}}{2}, \quad x = \frac{-11 + \sqrt{137}}{2} \]

Thus, these correspond to the answer:

\[ \frac{-11 - \sqrt{137}}{2}, \quad \frac{-11 + \sqrt{137}}{2} \]

So the solution is:

StartFraction negative 11 minus StartRoot 137 EndRoot Over 2 EndFraction comma StartFraction negative 11 plus StartRoot 137 EndRoot Over 2 EndFraction