How do you solve the quadratic equation by completing the square: x2+6x4=0?

1 Answer

Add 13 to both sides to make the left hand side a perfect square trinomial, then take the square root of both sides and subtract 3 to find:

x=3±13

Explanation:

Add 13 to both sides to get:

13=x2+6x+9=(x+3)2

(x+3)2=13

Take the square root of both sides to get rid of the exponent:

(x+3)2=±13

So x+3=±13

Subtract 3 from both sides to get:

x=3±13