Question

Please answer and put how

Answer 1

6 + m/4 = 3 (subtract 6 from both sides)
m/4 = -3 (multiply both sides by 4)
m = -12

Can plug in to original equation to check work:
6 - 12/4 = 3
6 - 3 = 3
3 = 3 

The answer m = -12 checks out

Answer 2

 first you write out the equation 
subtract 6 from both sides
then multiply both sides by 4
because if you multiply something to one side you have to do it to the other one too
m = -12
 you can then check work like this
6 - 12/4 = 3
6 - 3 = 3
3 = 3 

 (m = -12 subtract 6 from both sides)
(m/4 = -3 then you multiply both sides by 4)