Răspuns :
Notăm cu 'x' a doua fracție.
3/7•x=21/35;
x=21/35:3/7;
x=21/35•7/3; // Simplificăm:
=>x=7/5;
3/7•x=21/35;
x=21/35:3/7;
x=21/35•7/3; // Simplificăm:
=>x=7/5;
a × 3/7 = 21/35 |×35
a × 3 × 5 = 21
a × 15 = 21
a = 21/15
a = 7/5 (cealalta fractie)
Verificare:
7/5 × 3/7 = 21/35
a × 3 × 5 = 21
a × 15 = 21
a = 21/15
a = 7/5 (cealalta fractie)
Verificare:
7/5 × 3/7 = 21/35