Answer:
C = 1.
Step-by-step explanation:
x^2 - 2x = (x - 1)^2 - 1 so:
x^2 - 2x + C = (x - 1)^2 - 1 + C
So to get a perfect square C must be 1 ( as -1 + 1 = 0):-
(x - 1)^2 - 1 + 1 = (x - 1)^2
Checking this:
x^2 - 2x + 1
= (x - 1)(x - 1) which is a perfect square./
