4

Could you clarify what you want with "4"? Do you mean problem 4 from a set, or you want a quick practice on a topic?

If you share the exact question (or the subject and chapter), I can:

• solve problem 4 step-by-step, or
• give you a quick 4-question practice set on that topic, or
• explain the underlying concept with a couple of worked examples.

What would you prefer?