Question

calculati 3 supra23+6 supra23+9 supra 23+...+60 supra 23

Answer 1

3/23 + 6/23 + 9/23 +...+ 60/23 =
=(3+6+9+...+60)/23=
=3(1+2+3+4...+20)/23=
3*20*21:2:23=
3*10*21 :23=
30*21 :23=
631/23