Question

(3+4i)+(5-7i)=
(2-5i)-(4-9i)=
(2+3i)²=
(4+3i).(6+i)=

Answer 1

3+4i + 5-7i= 8 -3i

2-5i - (4-9i)= 2-5i-4+9i= -2+4i

(2+3i).(2+3i)= 4+6i+6i+9i²= 4+12i -9= -5+12i
lembrando que i²=-1

(4+3i).(6+i)= 24+4i+18i +3i²= 24+22i-3= 21+22i