It seems like you have provided an expression or part of an equation, but it's not completely clear. Based on what you wrote, it looks like you might be referring to something like:

• $-a - 4b$
• $3a + b$

If these are two separate expressions, there are various ways they could be manipulated. Could you clarify whether you want to:

1. Simplify the expressions.
2. Combine them into a single equation.
3. Solve for a particular variable, or something else?

Let me know how you'd like to proceed!

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Here are some follow-up questions to help further your understanding of the problem:

1. Are you trying to simplify or factor these expressions?
2. Do you want to solve for $a$ or $b$?
3. Is there an equation missing from the problem?
4. Would you like help understanding the relationship between the terms?
5. Would you like to explore similar problems involving these variables?

Tip: Always check if parentheses are needed to ensure the operations are done correctly.