221k views
3 votes
How do I even do this...

How do I even do this...-example-1
User Phz
by
3.7k points

1 Answer

4 votes

Answer:

x = 2 ±
√(15)

Explanation:

x² - 4x - 11 = 0 ( add 11 to both sides )

x² - 4x = 11

to complete the square

add ( half the coefficient of the x- term )² to both sides

x² + 2(- 2)x + 4 = 11 + 4

(x - 2)² = 15 ( take square root of both sides )

x - 2 = ±
√(15) ( add 2 to both sides )

x = 2 ±
√(15)

User Derek Stutsman
by
3.5k points