3ax-5 3a-11 2x+7
------------- + ---------- = ---------
(a-1)(x+3) a-1 x+3
3ax-5 3a-11 2x+7
------------- + ---------- - --------- =0
(a-1)(x+3) a-1 x+3
3ax-5 +3a-11(x+3) -2x+7(a-1)
------------------------------------------=0 (a-1)(x+3) не равно 0
(a-1)(x+3)
3ax-5 +3a-11(x+3) -2x+7(a-1)=0
3ax-5+3a-11x-33-2x+7a-7=0
дальше решай