Write the conjugate of.

If |z + 4| ≤ 3, then find the greatest and least values of |z + 1|.

for any two complex numbers z₁ and z₂ and any two real numbers a, b find the value of |az₁ – bz₂|² + |az₂ + bz₁|².

If n ∈ N, then find the value of iⁿ + i^{n + 1} + i^{n + 2} + i^{n + 3}.

Find the real value of a for which 3i³ – 3ai² + (1 – a) i + 5 is real.