题目内容：

x-4y分之3x + 4y-x分之x+y - x*x-4y分之7y

优质解答

x-4y分之3x + 4y-x分之x+y - x-4y分之7y
=3x/(x-4y)-(x+y)/(x-4y)-7y/(x-4y)
=(3x-x-y-7y)/(x-4y)
=(2x-8y)/(x-4y)
=2