Your b):  is it  sqrt(y-3) = y-3          or

                 sqrt(y) - 3 = y - 3  ?


To write it unambiguously, use parentheses properly and systematically
to denote / (to separate) different parts of the formulas.   


Otherwise, your formulas are ambiguous and unreadable.


This my notice relates to all your formulas a), b) and c).


When you write/prepare your post, do not use this symbol  √ ,  since when it comes to this forum, 
we, the readers, can not understand where the square root ends. Write something like sqrt(ax+b) instead.


Actually, the files in this forum are txt-files (plain text), so please write  your posts correspondingly.