We can expand the expression (a−b+c)2 by multiplying it by itself: (a−b+c)2=(a−b+c)(a−b+c) Now, we distribute each term in the first parentheses to each term in the second parentheses:
=a(a−b+c)−b(a−b+c)+c(a−b+c) =a2−ab+ac−ba+b2−bc+ca−cb+c2 Combine like terms:
=a2+b2+c2−ab−ba+ac+ca−bc−cb Since ab=ba, ac=ca, and bc=cb, we can simplify further: =a2+b2+c2−2ab+2ac−2bc Alternatively, we can use the formula (x+y+z)2=x2+y2+z2+2xy+2xz+2yz. In our case, x=a, y=−b, and z=c. So, (a−b+c)2=a2+(−b)2+c2+2(a)(−b)+2(a)(c)+2(−b)(c) =a2+b2+c2−2ab+2ac−2bc