Please help me out- i'm stuck on some questions regarding complex numbers. You don't have to do all of them, just as many as you can (and know)- Thanks in advance guys

1. -2+bi is a solution to z^2+az+[3+a]=0. Find a and b given they are real

2. Factorize z^4+2z^3-2z^2+8 into linear factors.

3. Find a quartic polynomial with rational coefficients having 2-i{3} and {2}+1 as two of its zeros

4. When P(x)= x^n +3x^2+kx+6 is divided by x+1 the remainder is 12. When P(x) is divided by x-1 the remainder is 8. Find k and n given that 34<n<38.