Question

Identify the number that needs to be added to both sides of the equation

Answer 1

Step 1

Given;

Step 2

$\begin{gathered} Half\text{ of the coefficent of x=}\frac{-8}{2}=-4 \\ Add\text{ \lparen-4\rparen}^2\text{ to both sides} \\ x^2-8x+(-4)^2=20+(-4)^2 \\ x^2-8x+16=36 \\ (x-4)^2=36 \end{gathered}$

Answer;

$16$