The sum of an infinite GP is `80/9` and its common ratio is `(-4)/5`. Find its first term.

Explanation

To find the first term of the infinite geometric progression (GP) given the sum and the common ratio, we can follow these steps:

### Step 1: Understand the formula for the sum of an infinite GP
The formula for the sum \( S \) of an infinite geometric progression is given by:
\[ S = \frac{a}{1 - r} \]
where \( a \) is the first term and \( r \) is the common ratio.
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