I have a hard time trying to figure it out how to derive the following sumations:(adsbygoogle = window.adsbygoogle || []).push({});

We know that:

P(z) = Sumation from j=0 to Infinity of [(Pj * (z^j)]

and

Q(z) = Sumation from j=0 to Infinity of [(Kj * ((z^j)]

Where j is a subindex for P and K, and a power for z.

Sumation from j=0 to Infinity of [ Sumation from i=0 to j+1 of [(z^j) * Pi * Kj-i+1] ]

Where i and j are a subindices for P and K, and a power for z.

I know that I have to play with the indices, but I have no clue. Any advice??

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# Problem with Sumations

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