You may want to review multiplying terms with roots and polynomials by monomials first.
If one factor has more than one term, you proceed just as if it was a polynomial. Multiply the other factor by each term. For example, to multiply a√a by −abc2√d − a, you multiply it by the first term (getting −a2bc2√(ad)) and by the second term (getting a2√a). So the answer is −a2bc2√(ad) − a2√a.
In this case, we couldn't simplify; but, if there are any simplifications to be done, we should do them.