If 9a2+25b2−c2+30ab=0 , then the set of lines ax+by+c=0 passes through the fixed point is

The given condition is 9a2+25b2−c2+30ab=0This can be rewrite as3a+5b2−c2=03a+5b−c3a+5b+c=0It implies that 3a+5b−c=0,  or 3a+5b+c=0 comparing the above equations with ax+by+c=0. x=−3,y=−5        or    x=3,y=5 Therefore, the fixed points are (−3,−5) or (3,5)