#### Answer

$y=(-4,-2)$

#### Work Step by Step

Step -1 : Add the square of half of the co-efficient of $y$ to both sides.
Co-efficient of $y = 6$
Half of $6 = \frac{1}{2}×6=3$
Square of $3$ is $3×3=9$
The equation becomes $y^2+6y+9=-8+9$
Step-2 Factor the trinomial and simplify the right hand side.
$(y+3)^2=1$
Step-3 Use the square root property and solve for $y$
$(y+3)=±\sqrt 1$
$y+3=±1$
Step-4 Subtract 3 on both the sides
$y=−3±1$
Therefore the solution set is $(-4,-2)$