How do I simplify this circuit to find resistor voltage?
Your approach, if not your execution, is sound .

If you're familiar with Thevenin equivalent circuits, you know that you can replace the entire circuit to the left of the B resistor with a voltage source in series with a resistor.  Once you've done this, voltage division will give you the voltage across B.

For A, replace all the resistors to the right of A with an equivalent resistor which is in parallel with A.  Then, once again, apply voltage division to find the voltage across A.