He's racking his brains about how to deal with the matter. ✬

How did you deal with the matter? ✬

He is hard to deal with. ✬

How would you deal with the problem? ✬

We have a lot of problems to deal with. ✬

We must deal with this problem. ✬

I have a lot of things that I must deal with. ✬

The situation was getting difficult to deal with. ✬

Who can deal with this difficult situation? ✬

He's a difficult person to deal with. ✬