Question

tg24 + tg21/ 1-tg21*tg24

Answer 1

$\frac{tg24^{0}+tg21^{0}}{1-tg24^{0}*tg21^{0}}=tg(24^{0}+21^{0})=tg45^{0}=1\\\\Otvet:\boxed{1}$