Yes, this is certainly ugly and scary.
Here's how to go about it:
-- Take the two resistors in the middle ... the 9 and the 8 .
They're in parallel.
Their equivalent resistance is something like 4.24 ohms. Whatever.
-- Take the two resistors around the outside on the right ... the 4 and the 6 .
Together, in series, they're equivalent to 10 ohms.
-- That 10 ohms is in parallel with the ~4.24 ohms in the box.
Now you have something like 2.98 ohms, all to the right of the 3 on top.
-- That 2.98 is in series with the 3.0 on top.
So there's 5.98 ohms.
-- The 20.0 is in parallel with the 5.98 ohms.
So that's about 4.6 ohms equivalent between 'A' and 'B'.
That's just off the top of my head. I won't sharpen it down
any further than that, because it's only 5 points, and you
should be able to do it now, using this approach.
