If-f-x-y-f-x-f-y-and-f-1-5-then-what-is-the-value-of-f-2020-

Question Number 93331 by john santu last updated on 12/May/20

$$\mathrm{If}\:\mathrm{f}\left(\mathrm{x}+\mathrm{y}\right)\:=\:\mathrm{f}\left(\mathrm{x}\right)+\mathrm{f}\left(\mathrm{y}\right)\:\mathrm{and} \\ $$$$\mathrm{f}\left(\mathrm{1}\right)=\mathrm{5}\:\mathrm{then}\:\mathrm{what}\:\mathrm{is}\:\mathrm{the}\:\mathrm{value} \\ $$$$\mathrm{of}\:\mathrm{f}\left(\mathrm{2020}\right)\:?\: \\ $$

Commented by mr W last updated on 12/May/20