# What number should be added to both sides of the equation to complete the square?

x^{2} + 8x = 4

**Solution:**

The following are the steps taken to complete the square while solving a quadratic equation :

- First, divide the coefficient of the term x by 2 and square the result.
- This number should be added to both sides of the equation

For the equation x^{2} + 8x = 4 the coefficient of the term x is 8

(8/2)^{2} = 16

The given equation can be written as

x^{2} + 8x + 16 = 4 + 16

x^{2} + 8x + 16 = 20

We can write it as

(x + 4)^{2} = 20

On both sides take square root

|x + 4| = √20

We get

x = 4 + √20

In other case,

- x + 4 = √20

x = 4 - √20

Therefore, 16should be added to both sides of the equation to complete the square x^{2} + 8x = 4.

## What number should be added to both sides of the equation to complete the square?

x^{2} + 8x = 4

**Summary:**

The number that should be added to both sides of the equation to complete the square x^{2} + 8x = 4 is 16.