Page 26 of Mathematics for Economics and Finance by M. Anthony and N. Biggs states the following equation, $y' = ay' + b$, and rearranges it as follows $(1 - a)y' = b$.
I do not understand how the authors rearrange this equation, so can anyone demonstrate this?
To add more context, the authors are concerned with finding a trivial, time-independent solution of a first-order linear recurrence. That is, they try to find a constant y' such that if yt-1 = y' then the recurrence equation ensures that yt has the same value as y'