To complete the square means that by adding or subtracting a constant to the equation, we have to take the left side of the equation to the form:
[tex](x-k)^2=x^2-kx+k^2\text{.}[/tex]
Now, notice that:
[tex]18x=2(9)x\text{.}[/tex]
Adding 81=9² to the equation we get:
[tex]x^2-18x+81=65+81.[/tex]
Therefore, we can rewrite the given equation as:
[tex](x-9)^2=146.[/tex]
Then:
[tex]x-9=\pm\sqrt[]{146}.[/tex]
Finally, we get that:
[tex]x=9\pm\sqrt[]{146}.[/tex]
Answer:
[tex]\begin{gathered} x_1=21.1, \\ x_2=-3.1. \end{gathered}[/tex]
