ANSWER:

There are two possibilities

Step-by-step explanation:

I think the question is to get 3p³ - 2p²q² *  + 4 pq not 3p³ - 2p³ q³ + 4 pq . Or the question should be LIKE What should be added to the sum of 3pq + 5p³ q³ + p³ *(instead of 3pq + 5p²q² + p³) and and p³ - pq to get 3p³ - 2p³ q³ + 4 pq?

So let me ADD the answer of both the possibilities

If the question is What should be added to the sum of 3pq + 5p²q² + p³ and p³ - pq to get 3p³ - 2p²q² + 4 pq?

Then the answer should be p³ + 2pq -7p²q²

Step by step explanation

3pq + 5p²q² + p³ +p³ - pq = 2p³ + 2pq + 5p²q²

Let X be the number added to get 3p³ - 2p³ q³ + 4 pq.

2p³ + 2pq + 5p²q² + x = 3p³ - 2p²q² + 4 pq.

x = p³ + 2pq -7p²q²

Thus, To get 3p³ - 2p²q² + 4 pq, 2p³ + 2pq + 5p²q²  must be added to p³ + 2pq -7p²q²

If the question is  What should be added to the sum of 3pq + 5p³ q³ + p³ and p³ - pq to get 3p³ - 2p³ q³ + 4 pq?

Then the answer will be

3pq + 5p³ q³ + p³ + p³ - pq = 2p³ + 2pq  + 5p³ q³

Let x be the number added to get 3p³ - 2p³ q³ + 4 pq

2p³ + 2pq  + 5p³ q³ +x =  3p³ - 2p³ q³ + 4 pq

x = p³ + 2 pq - 7 p³ q³