C-03-Q034mediumsingle_mcqSimplify: (5x+7y+3z)2+2(7x−7y−3z)(5x+7y+3z)+(7x−7y−3z)2(5x+7y+3z)^2 + 2(7x-7y-3z)(5x+7y+3z) + (7x-7y-3z)^2(5x+7y+3z)2+2(7x−7y−3z)(5x+7y+a(12x)2(12x)^2(12x)2b(12y)2(12y)^2(12y)2