Answer:
Explanation:
The sum of a geometric sequence can be found using the formula
Sn = a₁ (1 - rⁿ⁻¹)/ (1 - r)
where a₁ is the first term, r is the common ratio, and n is the number of terms.
In this case, a₁ = -8, r = -3, and n = 10.
Plugging these values into the formula, we get
Sn = -8 (1 - (-3)⁹⁻¹) / (1 - (-3))
Sn = -8 (1 + 3⁹) / 4
Sn = -8 (1 + 19683) / 4
Sn = -8 × 19684 / 4
Sn = -4920