Question

identify the missing factor (3^2a^3)(?) = -18a^6

Answer 1

If we call the missing factor x, you have this:
\[(3^{2}a^{3})(x)=-18a^{6}\]
Simplify:
\[(9a^3)(x) = -18a^{6}\]
Simplify further:
\[x = (-18 a^{6}) / (9a^{3}) = -2 a^{3}\]