The technique for solving this is called "completing the square".
Recognize that (x - p)2 = x2 - 2px + p2
Since the given equation begins with 2x2 , we first need to divide everything by 2 to get:
x2 + 3x/2 + 4 = 0 <----equation 1
From the 1st 2 terms, we can see that p = -3/4. We can now write:
(x - (-3/4))2 =
x2 + 3x/2 + 9/16
To make this match equation 1, put -4 +9/16 on the right to get:
x2 + 3x/2 + 9/16 = - 55/16
In the specified format:
(x + 3/4)2 = -55/16
thus p = -3/4, and q = -55/16
<<Edited to correct the mistake flagged by David W---it looks like the answer is still right>>


Mark H.
11/08/19
David W.
11/08/19