Respuesta :

The given equation is

[tex]x^2+x+9=0[/tex]

To complete the square, first, we have to move the independent term to the other side.

[tex]x^2+x=-9[/tex]

Then, we divide the linear coefficient by 2, then we apply a square power to it.

[tex](\frac{1}{2})^2=\frac{1}{4}[/tex]

We add this fraction to each side.

[tex]x^2+x+\frac{1}{4}=-9+\frac{1}{4}[/tex]

Then, we factor the trinomial and sum the numbers on the right side.

[tex]\begin{gathered} (x+\frac{1}{2})^2=\frac{-36+1}{4} \\ (x+\frac{1}{2})^2=\frac{-35}{4} \end{gathered}[/tex]

Then, to solve for x, we use a square root on both sides.

[tex]\begin{gathered} \sqrt[]{(x+\frac{1}{2})^2}=\pm\sqrt[]{-\frac{35}{4}} \\ (x+\frac{1}{2})=\pm\sqrt[]{-\frac{35}{4}} \end{gathered}[/tex]

As you can observe, the equation has no real solutions because the square root of a negative number can be solved in the real numbers.

Hence, the equation has no real solutions, and the number added to complete the square is 1/4.