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I have a multivariable polynomial, for instance: $P=yx+2^4xy+3+5^2xz+3^4zx $

I would like to do the following:

  1. extract those terms that only have $z$

  2. extract terms that only have $y$

  3. express my polynomial something like this: $P=z(...)+y(...)+(some\ constants)$

I know it's quite easy but this is just an example what I want to do. In reality, I have a polynomial with 60 terms, so I would like to know the procedure for doing this.

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  • $\begingroup$ tried Collect? $\endgroup$
    – kglr
    Jul 11 '19 at 9:14
  • $\begingroup$ Your example is bad since in fact the polynomial is 3 + 17 x y + 106 x z, which remains the same after vars = Variables[P];Collect[P, Rest[vars], Factor] $\endgroup$
    – Acus
    Jul 11 '19 at 9:17
  • $\begingroup$ @ user18792 the answer to this example is straightforward and supposed to be $P=z(3^4x+5^2x)+y(x+2^4x)+3$ $\endgroup$
    – Jason
    Jul 11 '19 at 9:20
  • $\begingroup$ @ kglr Thanks it worked $\endgroup$
    – Jason
    Jul 11 '19 at 11:51
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You can use Collect:

poly = Inactivate[y x + 2^4 x y + 3 + 5^2 x z + 3^4 z x, Power]
Collect[poly, {y, z}]

enter image description here

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