Concept:Use the algebraic identity (a−b)2=a2−2ab+b2.Explanation:Write (x−1)2 as (x−1)(x−1).Expand: (x−1)(x−1)=x2−x−x+1.Combine like terms: x2−2x+1.Now subtract 1 from the expansion:(x−1)2−1=(x2−2x+1)−1.Simplify: x2−2x+1−1=x2−2x.Thus, the simplified form is x2−2x.Answer:Option A: x2−2x