[tex](x + 7) {}^{4} = (x + 7) {}^{2 + 2} = > (x + 7) {}^{2} \times (x + 7) {}^{2} = > (x {}^{2} + 14x + 49) \times (x {}^{2} + 14x + 49) = {x}^{4} + 14x {}^{3} + 49x {}^{2} + 14x {}^{3 } + 196x { }^{2} + 686x + 49x {}^{2} + 686x + 2401 = > x {}^{4} + 28x {}^{3 } + 294x {}^{2} + 1372x + 2401.[/tex]
