\(a)\) \({\left( {x - 1} \right)^2}= {x^2} - 2x + 1\)
\(b)\) \({\left( {3 - y} \right)^2}=3^2-2.3.y+y^2\)\(= 9 - 6y + {y^2}\)
\(c)\) \({\left( {x - \dfrac{1}{2}} \right)^2} =x^2-2.x.\dfrac{1}{2}+\left(\dfrac{1}{2}\right)^2\)\(= {x^2} - x + \dfrac{1}{4}\)
