36（x+y）-49（x-y) =[ 6(x+y)+7(x-y) ] [ 6(x+y)-7(x-y) ] =(6x+6y+7x-7y) (6x+6y-7x+7y) =(13x-y) ( -x+13y )
36（x+y）-49（x-y)分解因式大神们帮帮忙
36（x+y）-49（x-y) =[ 6(x+y)+7(x-y) ] [ 6(x+y)-7(x-y) ] =(6x+6y+7x-7y) (6x+6y-7x+7y) =(13x-y) ( -x+13y )