To solve the equation 3x + 8 - 4x = x - 5, we need to simplify the equation by combining like terms on both sides.

First, let's combine the x terms on the left side:
3x - 4x = -1x

The equation now becomes:
-1x + 8 = x - 5

Now, let's get all the x terms on one side by subtracting x from both sides:
-2x + 8 = -5

Next, subtract 8 from both sides:
-2x = -13

Finally, divide by -2 to solve for x:
x = 13/2

Therefore, the solution to the equation 3x + 8 - 4x = x - 5 is x = 13/2.