Explicación paso a paso:
[tex] \\ (1 + 3{x}^{2} ) {}^{2} \\ = {1}^{2} + 2(3 {x}^{2} )(1) + (3 {x}^{2} ) {}^{2} \\ = 1 + 6 {x}^{2} + 9 {x}^{4} \\ \\ = 9 {x}^{4} + 6 {x}^{2} + 1[/tex]
[tex]1 + 6x {}^{2} + 9x {}^{4} \\ \\ 9x {}^{4} + 6x {}^{2} + 1 [/tex]
