3i (- 1 + 2i) Remove the brackets.
3i (-1) + (2i)(3i) Look at the first set of brackets around the -1
-3i + 6i^2 But i^2 = - 1[ I hope that's the way you are using it]
-3i - 6 or -6 - 3i or -3(2 - i) <<<<< answer
Step-by-step explanation:
best of luck dear.........
If you are looking for the expanded version, this is it. It is also possible to group either an a from (a^2 + 2b) or a b from (2ab + b^2). Hope this helps!
It is already in identity.
cos (x - y) - cos (x + y) = 2 sin(x) sin (y)
The answer is 2 cubed so B