Question

What number would you add to the equation below to complete the square?

Answer 1

Simplify the expression to obtain the completion of square.

`\begin{gathered} x^2+16x=0 \\ x^2+2\cdot8\cdot x+(8)^2=0+(8)^2 \\ x^2+2\cdot8\cdot x+64=64 \end{gathered}`

So 64 is added on both side of equation to obtain complete square.

Answer: 64.