Find the missing term!

if y=1+i, then y^3-3y^2 + (-3y,-3y+1,3y, 3i) - 1=-i

Y = 1 + i

(1 + i) ^3 - 3 * (1 + i) ^2 + k - 1 = - i

(1 + 3i + 3i^2 + i^3) - 3 * (1 + 2i + i^2) + k - 1 = - i

1 + 3i - 3 - i - 3 - 6i + 3 + k - 1 = - i

1 - 3 - 3 + 3 - 1 + 3i - i - 6i + k = - i

-3 - 4i + k = - i

k = 4i - i + 3

k = 3i + 3

k = 3 * (1 + i)

k = 3y