Respuesta :

Answer:

3(4+n)

Step-by-step explanation:

an=a+d(n-1)

an=15+3n-3=12+3n=3(4+n)

Answer:

3(4+n)

Step-by-step explanation:

an=a+d(n-1)

an=15+3n-3=12+3n=3(4+n)