设 z=a+bi
5(a+bi)+2i+(a+bi)i = 3
5a+5bi+2i+ai -b- 3=0
(5a-b-3) +(5b+2+a)i = 0
5a-b-3 = 0 且 5b+2+a=0
解得 a= 1/2 ,b= -1/2
∴ z = (1-i)/2
设 z=a+bi
5(a+bi)+2i+(a+bi)i = 3
5a+5bi+2i+ai -b- 3=0
(5a-b-3) +(5b+2+a)i = 0
5a-b-3 = 0 且 5b+2+a=0
解得 a= 1/2 ,b= -1/2
∴ z = (1-i)/2