Answer:
a3 = -25
Explanation:
Given an arithmetic sequence in which:
[tex]\begin{gathered} \text{ The first term,}a_1=-7 \\ \text{ The common difference, d}=-9 \end{gathered}[/tex]We want to find the 3rd term, a3.
The nth term of an arithmetic sequence is calculated using the formula:
[tex]a_n=a_1+(n-1)d[/tex]When n=3:
[tex]\begin{gathered} a_3=-7+(3-1)(-9) \\ =-7+2(-9) \\ =-7-18 \\ a_3=-25 \end{gathered}[/tex]The value of a3 is -25.
