Answer:
S12=855735
Step-by-step explanation:
if the 3rd term is 45 then,
formula: Sn=ar^n-1
S12=5*3^12-1
S12=5*3^11
S12=5*177147
S12=855735
When x is -1 Y will equal -1
Answer: 189
All Steps and Information Found in Image.
Hope This Helped!
$347.09 is the answer good luck