# How do you solve #x^2 + 3x +6 =0# by completing the square?

##### 2 Answers

# x = ± sqrt3 - 3 #

#### Explanation:

By adding 9 to both sides of the equation to obtain:

#( x^2 + 3x + 9 )+ 6 = 9# now

#(x + 3 )^ 2 = 9-6 = 3#

# ( x + 3 )^2 color(black)( " is a perfect square ") # Taking the 'square root' of both sides :

# sqrt((x+ 3 )^2 )= sqrt3# hence x + 3 = ±

#sqrt3 # so x = ±

#sqrt3 - 3 #

there are two

#### Explanation:

Completing the square method:

Do this only when the numerical coefficient of

Start with the numerical coefficient of

Divide this number by 2 then square the result. That is

Add

the first three terms now become one group which is a PST-Perfect Square Trinomial

Finally, transpose the

take note:

therefore

there are two