Question

关於二次根式(初二的)

化简:
(1)根号(x+y)^2(x-y)^2 (y>x>0)
(2)根号(2/3)^-2
(3)根号-(-8/5)^2
各位要顾及一下绝对值啊!!!
要写一写为什么会这样..谢谢了(不要只写答案)

Answer 1

化简:
(1)根号(x+y)^2(x-y)^2 (y>x>0)
=(x+y)(y-x)
=y²-x²
(2)根号(2/3)^-2
=根号(3/2)^2
=3/2
(3)根号-(-8/5)^2
这题你打错了吧，
改成-根号（-8/5)²就可以做了
-根号（-8/5)²=-8/5

Answer 2

(1)根号(x+y)^2(x-y)^2 =(x+y)(y-x)=y^2-x^2 (y>x>0)
(2)根号(2/3)^-2=根号(3/2)^2=3/2
(3)根号-(-8/5)^2无实数解

Answer 3

(1)=(x^2-y^2)2=x^4+y^4-2X^2y^2
(2)=(3/2)^2=9/4
(3)=-(8/5)^2=-64/25