Question

6.4=0.8m solve for m

Answer 1

6.4 = 0.8m
/0.8    /0.8
    8 = m

Answer 2

We want to isolate m so you find the value of it. To bring it over the equal sign and keep the equation even you simply do the opposite of it's current state (a value next to a letter always multiplies so you have to divide bringing it over the = sign).

6.4/0.8=m so m=8

Hope this helps and was easy to understand so you can do it on your own in the future.