Explicație pas cu pas:
daca (a,b,c)i.p.(2,3,7)=》a×2=b×3=c×7=k,unde k nr natural diferit de zero
a×2=k=>a=k/2
b×3=k=>b=k/3
c×7=k=>c=k/7, inlocuim in relatia 2b-a-c=1
2×k/3-k/2-k/7=1,aducem la numitor comun 42
14×2×k-21×k-6×k=42
28k-21k-6k=42
k=42
a=42/2=21
b=42/3=14
c=42/7=6
