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+1Note: - 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=x2−2xNote: (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+1Note: (−1)2=−1×−1=1(-x- = +)