First, we need to solve for m. To do this, lets get m on one side and the constants (just numbers) on the other side, so we:
[tex]6m+4=8m \\ subtract \\ 4=-2m \\ divide \\ m=-2[/tex]
First we subtract 6m from both sides. Then we divide by -2 to find out that m is equal to -2. Now, we need to find what 4m equals. So, we need to multiply m by 4:
[tex]4m \\ 4(-2) \\ -8[/tex]
4m is equal to -8.