code: def dup_expand(polys, K):
      """
      Multiply together several polynomials in ``K[x]``.
  
      Examples
      ========
  
      >>> from sympy.polys import ring, ZZ
      >>> R, x = ring("x", ZZ)
  
      >>> R.dup_expand([x**2 - 1, x, 2])
      2*x**3 - 2*x
  
      """
      if not polys:
          return [K.one]
  
      f = polys[0]
  
      for g in polys[1:]:
          f = dup_mul(f, g, K)
  
      return f
  
imports: from sympy.polys.densebasic import dup_slice, dup_LC, dmp_LC, dup_degree, dmp_degree, dup_strip, dmp_strip, dmp_zero_p, dmp_zero, dmp_one_p, dmp_one, dmp_ground, dmp_zeros
  from sympy.polys.polyerrors import ExactQuotientFailed, PolynomialDivisionFailed
label_desc: Use image node_id 63 for calling a global function with example usage: dup_expand(polys, K) and returns: f, list