Question Number 148733 by Rustambek last updated on 30/Jul/21
$${tg}\left(\alpha\right)+{tg}\left(\beta\right)=\mathrm{4} \\ $$$${cos}\left(\alpha\right)+{cos}\left(\beta\right)=\frac{\mathrm{1}}{\mathrm{5}} \\ $$$${tg}\left(\alpha+\beta\right)=? \\ $$