Answer:
The sum of the first 5 terms of the series is 77.
Step-by-step explanation:
1. Let's review the information provided to us for solving the sum of the first 5 terms of the series:
1st term = 7
2nd term = - 14
3rd term = 28
4th term = - 56
2. Let's solve the sum of the first 5 terms of the series:
Aₙ = Aₙ₋₁ * -2 ; A₁ = 7
A₁ = 7
A₂ = A₁ * -2 = 7 * - 2 = - 14
A₃ = A₂ * - 2 = -14 * - 2 = 28
A₄ = A₃ * - 2 = 28 * - 2 = - 56
A₅ = A₄ * - 2 = -56 * - 2 = 112
Sum of the first 5 terms of the series = 7 - 14 + 28 - 56 + 112
Sum of the first 5 terms of the series = 77
