For this equation, you cannot actually find the value of m, just simplify it.
So, the first step would be to distribute the negative. This is equal to 6

+ 3 -

- 4m +

- 2

+ 4m - 6.
Then, combine like terms.
Your final answer should be 7

- 3

- 3.
Hope this helps! If you need further assistance, message me or comment under this post!