Răspuns :
3 / 5 = 6 / 10 = 9 / 15 = 12 / 20 = 15 / 25 → fractii echivalente
( 3 × 2 ) / ( 5 × 2) = 6 / 10
( 3 × 5 ) / ( 5 × 5 ) = 15 / 20 → am amplificat cu 5 fractia
3 / 5 = 12 / 20 ⇒ 3 × 20 = 5 × 12 = 60
→ produsul mezilor = produsul extremilor
( 3 × 2 ) / ( 5 × 2) = 6 / 10
( 3 × 5 ) / ( 5 × 5 ) = 15 / 20 → am amplificat cu 5 fractia
3 / 5 = 12 / 20 ⇒ 3 × 20 = 5 × 12 = 60
→ produsul mezilor = produsul extremilor