Răspuns:
[tex](a - b)^{2} = {a}^{2} - 2ab + {b}^{2} [/tex]
[tex]3(x - 3)(x + 2) = 3( {x}^{2} - x - 6) = \\ 3 {x}^{2} - 3x - 18[/tex]
[tex]e(x) = 4 {x}^{2} - 4x + 1 + 3 {x}^{2} - 3x \\ - 18 + {x}^{2} - x + 1[/tex]
[tex](x - 2)(x + 1) = {x}^{2} - x - 2[/tex]
[tex] {(2x - 1)}^{2} = 4 {x}^{2} - 4x + 1[/tex]
