How do you factor (x-1)^2 - 4?

2 Answers
May 12, 2018

(x-3)(x+1)

{3,-1}

Explanation:

(x-1)^2-4

Factor out:

x^2-2x+1-4
=
x^2-2x-3

Factor:

(x-3)(x+1)

{3,-1}

May 12, 2018

(x+1)(x-3)

Explanation:

Expression = (x-1)^2-4

To factorise the expression we could first expand the first term. However, in this case, notice that the expression is the difference of two squares.

Expression = (x-1)^2 - 2^2

Remember the common identity: a^2 - b^2 = (a+b)(a-b)

Thus, Expression = (x-1+2)(x-1-2)

= (x+1)(x-3)