Question

Let x^2+ 6x = 5

What values make an equivalent number sentence after completing the square?
Enter your answers in the boxes.
x² +6x+ ____=_____

Answer 1

9

Explanation:

For the equation x² - 6x = 5 the coefficient of the term x is -6

(-6/2)2 = 9

The given equation can be written as

x2 - 6x + 9 = 5 + 9

x2 - 6x + 9 = 14

We can write it as

(x - 3)2 = 14

Take square root on both sides.

|x - 3| = √14

We get

x = 3 + √14

In other case,

- x + 3 = √14

x = 3 - √14

Therefore, 9 should be added to both sides of the equation to complete the square (x2 - 6x = 5).

What number should be added to both sides of the equation to complete the square (x2 - 6x = 5)?

Summary:

The number that should be added to both sides of the equation to complete the square (x2 - 6x = 5) is 9.