Question

Solve the quadratic equation by completing the square.
x2 + 6x + 7 = 0

a:36+-squareroot2
b:3+-squareroot11
c:-3+-sqaueroot2

Answer 1

(x+3)^2-2 = 0

Can you do the rest?

Answer 2

1. Move the number to the opposite side of the equal sign.
x2+6x=-7
2. The term with the x, divide in half, then square it.
6/2=3 3^2=9
3. Add that number on both sides of the equation.
x2+6x+9=-7+9
4. Solve the perfect square
(x+3)^2=2
5. Take the square root on both sides of the equation
x+3=+-sqrt(2)
6. Equal the term on the left to the positive and negative roots.
Since it's only one term, it's only a matter of solving for x
x=-3+-sqrt(2)