Respuesta :

Given:

[tex]\begin{gathered} a_1=-15 \\ d=-3 \\ a_n=-24 \end{gathered}[/tex]

To find:

The value of n.

Explanation:

The nth term formula for the arithmetic sequence is,

[tex]a_n=a_1+(n-1)d[/tex]

Substituting the given values we get,

[tex]\begin{gathered} -24=-15+(n-1)(-3) \\ -24=-15-3n+3 \\ -24=-3n-12 \\ -3n=-24+12 \\ -3n=-12 \\ n=4 \end{gathered}[/tex]

Thus, -24 is the 4th term of the sequence.

Final answer:

The term -24 is the 4th term of the sequence.