Descompunem numerele intregi in factori primi
2970=2*3^3*5*11
7920=2^4*3^2*5*11
Luam toti factorii primi ,la puterile cele mai mici
cmmdc: (2970; 7920)=2*3^2*5*11=990
Impartim numaratorul si numitorul fractiei ,la cmmdc
2970 (2*3^3*5*11) (( 2*3^3*5*11):(2*3^2*5*11)) 3 3
------- = ------------------ = ---------------------------------------- = ------ = ---
2920 2^4*3^2*5*11 (( 2^4*3^2*5*11):(2*3^2*5*11)) 2^3 8
3:8=0,375 (ca nr.zecimal)
2970 3
------ = --- (ca fractie subunitara)
7920 8
2970
------- = 0,375 (ca nr.zecimal)
7920