1. The problem is to write an expression or equation in a clean, simplified form. 2. To clean or simplify an expression, combine like terms, factor where possible, and write it in the neatest way. 3. For example, if you have an expression like $$2x + 3x - 4 + 6$$, combine like terms: $$2x + 3x = 5x$$ and $$-4 + 6 = 2$$. 4. So the clean form is $$5x + 2$$. 5. Always check if you can factor or simplify further, but if not, this is the clean form.