x2+6x+5=0 First of all half the x coefficient and write (x+6/2)2 the take away the (6/2)2 and add on the 5
(x+3)2-9+5=0
(x+3)2-4=0 Simplify the expression
(x+3)2=4 Move 4 to the other side of the equation so you can square root both sides
x+3=+-2 Take the square root of both sides
x=-5, x=-1 Take 3 away from both sides to find the 2 values of x that solve the equation