For the AP ` -3, -7, -11, …` can we find directly `a_(30)-a_(20)` without actually finding `a_(30)` and `a_(20)` ? Give reason for your answer.

Explanation

To find \( a_{30} - a_{20} \) for the arithmetic progression (AP) given as \( -3, -7, -11, \ldots \), we can use the properties of arithmetic progressions without directly calculating \( a_{30} \) and \( a_{20} \).

### Step-by-Step Solution:

1. **Identify the first term and common difference**:
- The first term \( a = -3 \).
- To find the common difference \( d \), we calculate:
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