Question

What integer needs to be added to the expression to create a perfect square? x2 - 2x
A. -4
B. -1
C. 1
D. 4

Answer 1

The answer is C.

x² - 2x +1
x² - x - x + 1
x(x) - x(1) - 1(x) + 1(1)
x(x - 1) - 1(x - 1)
(x - 1)(x - 1)
(x - 1)²