كنت قد سألت هذا السؤال في المنتدى وقد اجابني الاستاذ صلاح السلول فكانت اجابته كما يلي:

a+(a+d) +(a+2d) +(a+3d)=360

2a+3d=180

a is positive and d is positive


d=60-2/3 a

then60-2/3 a is positive so a is less than 90

and geater than 0

then we seethat the problem with this condition has many infinitely solutions