Answer:

Step-by-step explanation:
Given

Required
Solve

Split:
and
Collect Like Terms
and 
and 
Combine

Gotta see a pic of the paper
Answer:
an = -3·2^(n-1)
Step-by-step explanation:
The first term is a1 = -3.
The common ratio is r = -6/-3 = 2.
The given formula tells you the formula for this sequence is ...
an = -3·2^(n-1)

the decimals are commas and the double decimal is a real decimal