Question

Solve by factoring. x2 + 6x = - 9. Hint: This is a double root.

Answer 1

Subtract -9 from both sides.

x2+6x−(−9)=−9−(−9)

x2+6x+9=0

Factor left side of equation.

(x+3)(x+3)=0

Set factors equal to 0.

x+3=0 or x+3=0

x=−3

Answer:

x=−3

Answer 2

1
 Move all terms to one side

x^2+6x+9=0

2 
Rewrite x^2+6x+9 in the form a^2+2ab+b^2 , where a=x and b=3

x^2+2(x)(3)+3^2=0

3 
Use Square of Sum (a+b)^2=a^2+2ab+b^2

(x+3)​^2​​=0

4 
Take the square root of both sides

x+3=0

5 
Subtract 3 from both sides

x=−3

So, in short, your answer is x = - 3


I hope this helps, and have a great day. :)