[tex] {(x + 4)}^{2} = {x}^{2} + 8x + 16[/tex]
[tex] {(2x + 1)}^{2} = 4 {x}^{2} + 4x + 1[/tex]
[tex] {(3x - 2)}^{2} = 9 {x}^{2} - 12x + 4[/tex]
[tex](x - \sqrt{7} )(x + \sqrt{7} ) = {x}^{2} - 7[/tex]
