1) 8-5i+15+2i=23-3i;
2) 8-5i-15-2i=-7-7i=-7(1+i);
3) (8-5i)(15+2i)=120+16i-75i-10i²=120-59i+10(-1)²=130-59i;
4) (8-5i)/(15+2i)=(8-5i)(15-2i)/(15+2i)(15-2i)=((120-16i-75i+10i²)/15²+2²=(120-91i-10)/225-4=(110-91i)/221
1) 8-5i+15+2i=23-3i;
2) 8-5i-15-2i=-7-7i=-7(1+i);
3) (8-5i)(15+2i)=120+16i-75i-10i²=120-59i+10(-1)²=130-59i;
4) (8-5i)/(15+2i)=(8-5i)(15-2i)/(15+2i)(15-2i)=((120-16i-75i+10i²)/15²+2²=(120-91i-10)/225-4=(110-91i)/221