The last one , because I will now solve it for you and prove therefore.
x²–4x+5=0;
D=(–4)²–4•5=16–20= –4= (2i)².
So:
x1= (4–2i)/2= 2–i
x2= (4+2i)2= 2+i.
This is the whole answer....
Three other u will solve by yourself and have roots which will not be suitable.
