You need to isolate all the unknowns on one side and the numbers on the other.
So:
Adding 4x to both sides to cancel the (-4x) on the LHS gives:
13 = 1 -x + 4x
Now takeaway one to cancel the one on the RHS:
13 - 1 = 4x -x
12 = 3x Now divide by the times of x
x = 12/3
x = 4
Hope that helped!
