7+3x-12x=3x+1
We will first make all the numbers which have x in go to the left.
So 7+3x-12x-3x, we make the 3x negative since to make it move it needs to change.
Then we will make all the sevens go to the right, so 3x-12x-3x=1-7.
So now it is much easier to figure out.
-12x=-6