Question

26 efetue (2+5i).(1-i)

Answer 1

2.1-2i+5i-5i ² =0
2-2i+5i - 5i ² 
2-3i+5i ² 

-b√ b² -4.a.c
3√-3²-4.2.5
3√9-20
3√-11