Answer: 12i + 21
Step-by-step explanation:
You want to apply foil to the first two terms.
- 3 x 1 = 3
- 5i x 3 = 15i
- -4i x 1 = -4i
- -4i x 5i = -20i^2
You get 3 + 11i - 20i^2. i is equal to the square root of -1, so when you square it, you will get -1. Then do -1 x -20 to get +20
So far you have (11i + 23) - (-i + 2).
- 11i + i = 12i
- 23 - 2 = 21
Im 99% sure the answer is 12i + 21
