Answer:
b = -1/10.
Step-by-step explanation:
(2i/2+i)-(3i/3+i)
= 2i(3 + i) - 3i(2 + i) / (2 + i)(3 + i)
= 6i + 2i^2 - 6i - 3i^2 / (2 + i)(3 + i)
= (-2 + 3) / (6 + 5i - 1)
= 1 / (5 + 5i)
Now we multiply top and bottom by 5 - 5i :
= 5 - 5i / (5 + 5i)(5 - 5i)
= 5 - 5i / 25 -25i^2
= 5 - 5i / 50
= 1/10 - 1/10i
