Question

定义运算

.

a b c d

.

=ad-bc，若复数x=

2-i

3+i

，y=

.

4i 3-xi 1+i x+i

.

，则y=______．

Answer 1

x=

2-i

3+i

=

(2-i)(3-i)

(3+i)(3-i)

=

5-5i

10

=

1

2

-

1

2

i
y=

.

4i 3-xi 1+i x+i

.

=4xi-4-（3+3i-xi+x）=5xi-7-3i-x=-5
故答案为：-5