الاجابة
(15ax – 10bx + 5cx) + (12ay – 8by + 5cy) + (15az – 10bz + 5cz) =
5x(3a – 2b + c) + 4y(3a – 2b + c) + 5z(3a – 2b + c) =
(5x + 4y + 5z)(3a – 2b + c) =