Answer:
[tex]a_5=-4[/tex]
Step-by-step explanation:
[tex]a_n=a_{n-1}-3\\\\a_1=8\\\\a_2=a_1-3\to a_2=8-3=5\\\\a_3=a_2-3\to a_3=5-3=2\\\\a_4=a_3-3\to a_4=2-3=-1\\\\a_5=a_4-3\to a_5=-1-3=-4[/tex]