Question

已知3a^2+ab-2b^2=0,求代数式a/b-b/a的值

Answer 1

3a^2+ab-2b^2=0
(3a-2b)(a+b)=0
3a=2b ==> a/b-b/a = 2/3 - 3/2 =-5/6
or a=-b ==> a/b - b/a = 0

Answer 2

3a^2+ab-2b^2=0
(a+b)(3a-2b)=0
a =b or a= 2b/3

when a=b
a/b -b/a
1-1 =0
when a=2b/3
a/b -b/a
=2/3 - 3/2
= -5/6