a2=a×a (x−1)2=(x−1)×(x−1) Expand the bracket by taking each expressions in the first bracket to multiply the second bracket and simplify. (x−1)2=x×(x−1)−1×(x−1) (x−1)2=x×x−1×x−1×x−1×−1 (x−1)2=x2−x−x+1 Note: - x−=+ (x−1)2=x2−2x+1 (x−1)2−1=x2−2x+1−1 (x−1)2−1=x2−2x+0 (x−1)2−1=x2−2x Note: ( expression )2= The first number squared +2x the first number and the second number + second number squared. (x−1)2=x2+2×x×(−1)+(−1)2 (x−1)2=x2−2x+1 Note: (−1)2=−1x−1=1(−x−=+)