Question

Write x2 - 2x - 3 = 0 in the form (x - a)2 = b, where a and b are integers.
(x - 4)2 = 3
(x - 3)2 = 2
(x - 2)2 = 1
(x - 1)2 = 4

Answer 1

We have:
x^2 - 2x - 3 = 0

To complete the square, we take the middle number, halve it and then square it.
(-2 / 2)^2 = 1
Now we have the answer, '1', we add this and take it to the end of the equation:
x^2 - 2x + 1 - 1 - 3 = 0

This then allows us to simplify the first part as a perfect square:
x^2 - 2x + 1 - 1 - 3 = 0
(x - 1)^2 - 1 - 3 = 0
(x - 1)^2 = 4

So the answer is: (x - 1)^2 = 4

ANSWER IS D