Answer:
[tex]A=-5+9i[/tex]
Step-by-step explanation:
[tex]\left(3+4i\right)-\left(8-5i\right)\\\\\mathrm{Group\:the\:real\:part\:and\:the\:imaginary\:part\:of\:the\:complex\:number}\\\left(a+bi\right)\pm \left(c+di\right)=\left(a\:\pm \:c\right)+\left(b\:\pm \:d\right)i\\\\=\left(3-8\right)+\left(4+5\right)i\\3-8=-5\\4+5=9\\\\=-5+9i[/tex]
