Question

Solve the equation for all values of x by completing the square. x²+8x=-15

Answer 1

`x^2+8x=-15`

since (8/2)^2=16, we will add 16 in both sides of the equation, obtaining

`x^2+8x+16=1`

now, we factor the left side of the equation (it's a perfect square)

`(x+4)^2=1`

then we have two options or x+4=1 or x+4=-1

solving both of the we have that the values for x are x=-3 and x=-5