x²–14x
To the side:
Multiply -14 by
, getting -7
Square -7, getting (-7)² or +49
Make the zero sum +49-49, and add that
to the given expression:
x²-14x+49-49
Factor the first three terms
(x-7)(x-7)-49
Write that as
(x-7)²-49
Put a 1 in front of the binomial squared:
1(x-7)²-49
That is in the form
a(x+b)+c
a=1, b=-7, c=-49
Edwin