How to find general term?

Q1.
4 ,-16, 64,-256...

It is a geometric sequence with
first term a = 4;
and common ratio r = -4

General term T(n)
= arn-1
= 4 x (-4)n-1
= 4 x [(-1)n-1 x 4n-1]
= (-1)n-1 x (4)n

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Q2.
-2/3, 4/9, -8/27, 16/81 ,-32/243...

It is a geometric sequence with
first term a = (-2/3);
and common ratio r = (-2/3)

General term T(n)
= arn-1
= (-2/3) x (-2/3)n-1
= (-2/3) x [(-1)n-1 x (-2/3)n-1]
= (-1)n-1 x (-2/3)n
=