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复数(5+5i)3(3−4i)4+3i=()A.−105i−105B.105+105iC.105−105iD.−105+105i

题目详情
复数
(
5
+
5
i)3(3−4i)
4+3i
=(  )

A.−10
5
i−10
5

B.10
5
+10
5
i
C.10
5
−10
5
i
D.−10
5
+10
5
i
▼优质解答
答案和解析
(
5
+
5
i)3(3−4i)
4+3i
=
10i(
5
+
5
i)(3−4i)
4+3i

=
10
5
+70
5
i
4+3i
=
(10
5
+70
5
i)(4−3i)
25

=
250
5
+250
5
i
25
=10
5
+10
5
 i,
故选 B.