+128399 3. Here's a trick to always try on this kind of problem, NSS
Look at the second denominator.....see if the first actually factors with this
Notice that the first denominator is ( b - 1) (b + 2)
So we have...also factoring the top of the first fraction
(b - 4) ( b + 2) 6
___________ - _____
(b - 1) (b + 2) b - 1
(b - 4) 6
_____ - ____
(b - 1) (b - 1)
( b - 4 - 6 )
_________
(b - 1)
b - 10
______
b - 1
