i是虚数单位,若-1+3i/1+2i=a+bi(a,b属于实数,)则a-b的值是

问题描述:

i是虚数单位,若-1+3i/1+2i=a+bi(a,b属于实数,)则a-b的值是

-1+3i/1+2i
=(-1+3i)(1-2i)/(1+2i)(1-2i)
=(5+i)/5
=1+1/5i
=a+bi
a=1 b=1/5
a-b=4/5