C CosmicAnon New member Joined Mar 20, 2018 Messages 1 Feb 20, 2019 #1 instructions: factor each difference of two squares. Assume that any variable exponents represent whole numbers. a^2 - (b-2)^2 My work: a^2 -(b-2)(b+2) I know the answer is (a+b-2)(a-b+2) I just don’t understand how to get there. Why is the a inside the parentheses? How did it get there?

instructions: factor each difference of two squares. Assume that any variable exponents represent whole numbers. a^2 - (b-2)^2 My work: a^2 -(b-2)(b+2) I know the answer is (a+b-2)(a-b+2) I just don’t understand how to get there. Why is the a inside the parentheses? How did it get there?

S Subhotosh Khan Super Moderator Staff member Joined Jun 18, 2007 Messages 18,135 Feb 20, 2019 #2 In your response, you expanded (b-2)^2 as (b-2)(b+2). That is incorrect. There is no need to expand (b-2)^2. You need to use: x^2 - y^2 = (x+y) * (x-y) For your problem: x = a and y = (b-2) continue....

In your response, you expanded (b-2)^2 as (b-2)(b+2). That is incorrect. There is no need to expand (b-2)^2. You need to use: x^2 - y^2 = (x+y) * (x-y) For your problem: x = a and y = (b-2) continue....

Jomo Elite Member Joined Dec 30, 2014 Messages 3,018 Feb 20, 2019 #3 Even if (b-2)^2 = (b+2)(b-2) you did not factor anything, you expanded things!