设复数i−21+i=a+bi (a,b∈R),则a+b=_.

问题描述:

设复数

i−2
1+i
=a+bi (a,b∈R),则a+b=______.

i−2
1+i
=
(−2+i)(1−i)
(1+i)(1−i)
=
−1+3i
2
=-
1
2
+
3
2
i=a+bi,
∴a=-
1
2
,b=
3
2
,∴a+b=1,
故答案为:1.