Find the sum
(i) `1+(-2)+(-5)+(-8)+ … +(-236)`
(ii) `(4-(1)/(n))+(4-(2)/(n))+(4-(3)/(n))+ …` upto `n` terms.
(iii) `(a-b)/(a+b)+(3a-2b)/(a+b)+(5a-3b)/(a+b)+ … ` to 11 terms.

Explanation

Let's solve the given questions step by step.

### Part (i): Find the sum of the series \(1 + (-2) + (-5) + (-8) + \ldots + (-236)\)

1. **Identify the series**: The series is \(1, -2, -5, -8, \ldots, -236\).
2. **Find the common difference**:
- \(a_1 = 1\)
- \(a_2 = -2\)
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