f1.
[tex] \frac{20}{2 - i} = a + bi \\ amplificam \: cu \: conjugaul \: (2 + i) \\ = > \frac{20(2 + i)} {(2 + i)(2 - i)} \\ \frac{40 + 20i}{4 + 1} \\ = 8 + 4i \\ = > a = 8 \: \: b = 4 \\ \\ [/tex]
2. f(x)=x^2+x-1
f(0)=-1
f(1)=1
(f(0))^2017+(f(1))^2017=(-1)^2017+(1)^2017
=-1+1
=0