（2+5i)/3i+(√3+i)(√3-i)
= -(2/3)i +5/3 +(3+1)
=17/3-(2/3)i= -(2/3)i +5/3 +(3+1)=17/3-(2/3)i答案没错，我就是想知道这两步是怎么算的(√3+i)(√3-i)=(√3)^2-(i)^2= 3+1=4(2+5i)/3i=2/(3i) + 5i/(3i)= 2i/(3i^2) + 5/3= -(2/3) i +5/3