Question

Find the solutions for the quadratic equation by completing the square.
`x ^(2) + 18x = 63`

Answer 1

Completing the square

`x^2+18x=63`
`\begin{gathered} x^2+18x+((18)/(2))^2=63+((18)/(2))^2 \\ x^2+18x+81=63+81 \\ x^2+18x+81=144 \\ (x+9)^2=144 \\ \end{gathered}`
`\begin{gathered} (x+9)=\sqrt[]{144} \\ x+9=\pm12 \\ x_1=-12-9 \\ x_1=-21 \\ \\ x_2=12-9 \\ x_2=3 \end{gathered}`

The answer would be -21, 3