tolong minta bantuannya sama caranya yaa soal gmpang kok

soal yg terakhir

[tex]f(g) = {x}^{2} + 4 \\ ( {2x + 1)}^{2} + 4 \\ {4x}^{2} + 4x + 1 + 4 \\ = {4x}^{2} + 4x + 5[/tex]
jwban B