Answer:
- 405
Step-by-step explanation:
the recursive formula given allows us to find the next term in the sequence by multiplying the previous term by - 3
[tex]b_{2}[/tex] = [tex]b_{1}[/tex](- 3) = 15 × - 3 = - 45
[tex]b_{3}[/tex] = [tex]b_{2}[/tex](- 3) = - 45 × - 3 = 135
[tex]b_{4}[/tex] = [tex]b_{3}[/tex](- 3) = 135 × - 3 = - 405
