Hello,
If we use the Pascal triangle:
1
1|1
1|2|1
1|3|3|1
1|4|6|4|1
1|5|10|10|5|1
1|6|15|20|15|6|1
1|7|21|35|35|21|7|1
1|8|28|56|70|56|28|8|1
1|9|36|84|126|126|126|84|36|9|1
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I support your ask is concerned with descending exponients
The answser is 84*(3x)^3*(9^6)=1205308188 x^3