Răspuns:
[tex]\displaystyle{ = 12^{n} \cdot 49 }[/tex]
Explicație pas cu pas:
[tex]\displaystyle{ 12^{n} + 3^{n+1} \cdot 4^{n+2} = }[/tex]
[tex]\displaystyle{ = 12^{n} + 3^{n} \cdot 3 \cdot 4^{n} \cdot 4^{2} }[/tex]
[tex]\displaystyle{ = 12^{n} + 12^{n} \cdot 3 \cdot 4^{2} }[/tex]
[tex]\displaystyle{ = 12^{n} \cdot (1 + 3 \cdot 16) }[/tex]
[tex]\displaystyle{ = 12^{n} \cdot 49 }[/tex]