Question

$\sqrt{ \frac{1 + 3 + 5 + ... + 47}{1 + 3 + 5 + ... + 23} }$
va rrog dau coroana cine raspunde primul

Answer 1

1+3+5+....47=1+2+3+...46+47-(2+4+6+..46)=47*48/2-2(1+2+23)=47*24-2*23*24/2=24*(47-23)=24*24
1+3+..+23=23*24/2-2(1+2+..12)=23*12-2*12*13/2=12*12
Expresia va fi egala cu rad(2*2)=2