<PRE><B>Question 196753</B>
Completing the square requires half the coefficient of x to be used (when the coefficient of x^2 is 1) so that we have a square on one side and since this isn’t 0 generally we have it equal to whatever we have to adjust the equation to which is 3 in this example.


(x + 4)^2 = x^2 + 8x + 16 so


x^2 + 8x + 13 = (x^2 + 8x + 16) - 3 = 0


(x + 4)^2 - 3 = 0


(x + 4)^2 = 3


Therefore


x + 4 = + or - square root of 3


x = - 4 + or - square root of 3</PRE>