Completely factor the expression by grouping, if possible.
6ac−3bd+bc−18ad
To factor by grouping, we can group the terms in pairs:
(6ac - 3bd) + (bc - 18ad)
Now, let's factor out the greatest common factor from each pair:
3ac(2 - bd) + b(c - 18ad)
We can see that the two terms now have a common factor of (c - 18ad), so we factor that out:
(c - 18ad)(3ac + b)