Question

Find the missing term. If y = 1 + i, then y3 − 3y2 + (-3y) (-3y + 1) (3y) (3i ) − 1 = -i .

Answer 1

Filling in y=1+i without the missing term yields -3-4i.

-3-4i = -3(1+i) - i

So we have to add 3(1+i) to get to -i.

3(1+i) = 3y, so 3y is the answer.