若x/x2−x−2=a/x+1+b/x−2(a、b为常数),则a=_,b=_.

问题描述:

x
x2−x−2
=
a
x+1
+
b
x−2
(a、b为常数),则a=______,b=______.

x
x2−x−2
=
a
x+1
+
b
x−2

x
x2−x−2
=
a(x−2)
x2−x−2
+
b(x+1)
x2−x−2

∴x=(a+b)x-2a+b,
∴a+b=1,-2a+b=0,
解得a=
1
3
,b=
2
3

故答案为
1
3
2
3