13-4x=1-x
First,I would move my x's to the right and my numbers to the left so...
13-4x=1-x
+4x +4x
-------------------
13=1+3x
-1 -1
----------------
12=3x
Now, you would divide 3 from both sides.
12=3x
---- ----
3 3
Solution: 4=x
To check the solution, plug in 4 for x.
13-4(4)=1-4
13-16=-3
-3=-3
The solution works, therefore
x=4