Answer: the 10th term is - 5120
Explanation:
In a geometric sequence, consecutive terms differ by a common ratio.
The formula for determining the nth term of a geometric progression is expressed as
an = a1r^(n - 1)
Where
a1 represents the first term of the sequence.
r represents the common ratio.
n represents the number of terms.
From the information given,
a1 = 10
r = - 20/10 = 40/ - 20 = - 2
n = 10
The 10th term, T10 is
T10 = 10 × - 2^(10 - 1)
T10 = 10 × - 2^9
T10 = 10 × - 512
T10 = - 5120