Answer:
31.25
Step-by-step explanation:
The general form of a complete square would be (x + a)^2 + b
Given an equation of X^2 + 15X + 25 = 0,
the idea is to reduce it into the form if (X + C)^2
which can be expanded into X^2 + 2XC + C^2
In this case 15 will be our 2C So our c will be 7.5.
Substituting in these numbers,
We have X^2 + 15X + (7.5)^2 = 0
However our original equation has 25 for its C^2, thus
we need to add 31.25 in order to get (7.5)^2
FYI
The final completed form will be (X + 7.5)^2 - 31.25
