(5 25/129+а)-7 19/86=4 25/258+5 104/172 решить уровнение

(5 25/129+a)-7 19/86=4 

[(√b+3)/(√b-3) +(√b-3)/(b√+3) - 36/(b-9)]^-2=
[(b+6√b+9+b-6√b+9-36)/(b-9)]^-2=[(2b-18)/(b-9)]^-2=[2(b-9)/(b-9)]^-2=(2)^-2=1/4