Question

media aritmetica a 13 nr este egal 74

Answer 1

x+x+1+x+2+x+3+x+4+x+5+x+6+x+7+x+8+x+9+x+10+x+11+x+12 totul impartit la 13= 74
apoi aduni x si rezulta 13x+78 totul impartit la 13= 74
apoi 13x+78= 74*13
13x+78=962
13x=962-78
13x=884
x= 68.