How do you put 3y+x=12 in y=mx+b form

Step 1: Rewrite the equation

3y+x=12

Step 2: To get y alone on the left side, subtract x on both sides

3y+x=12
-x -x

3y=-x+12

Step 3 (final step): To get y alone, divide each number by 3

3y = -x +12
/3 /3 /3

y=-1/3x+4

Final y=-1/3x+4

Hope this helps :)