The First-Ever IMO Problem Has a Beautiful One-Line Proof

This was the first-ever problem in IMO history. For every positive integer n, prove that (14n+3)/(21n+4) is always in lowest terms. #maths #imo #numbertheory #mathematics #olympiadmathquestion #mathproofs #problemsolving #modulararithmetic #mathchallenge #advancedmaths #puremathematics #mathematicalbeauty #learnmath #mathyoutube