已知y-2x=0,求3x²-2y²/(x+y)(x-y)的值

已知y-2x=0,求3x²-2y²/(x+y)(x-y)的值
已知y-2x=0,求3x²-2y²/(x+y)(x-y)的值

已知y-2x=0,求3x²-2y²/(x+y)(x-y)的值
你直接把Y=2X带进式子里面去啊.

y=2x
（3x平方-8x平方）÷（3x乘（-x））
=3分之5

等于5/3