# How do you solve using completing the square method #m^2+4m+2=0#?

##### 1 Answer

Oct 5, 2016

#### Explanation:

The difference of squares identity can be written:

#a^2-b^2 = (a-b)(a+b)#

Use this with

#0 = m^2+4m+2#

#color(white)(0) = m^2+4m+4-2#

#color(white)(0) = (m+2)^2-(sqrt(2))^2#

#color(white)(0) = ((m+2)-sqrt(2))((m+2)+sqrt(2))#

#color(white)(0) = (m+2-sqrt(2))(m+2+sqrt(2))#

Hence:

#m = -2+-sqrt(2)#