a si b numerele
a : 5 = b :7 => 7×a = 5 × b => a = 5×b :7
a : 4 + b : 4 = 75 | ×4
a + b = 75 × 4
a + b = 300
inlocuim pe a cu 5 × b :7
5 × b :7 + b = 300 | ×7
5×b + 7 × b = 2 100
12 × b = 2 100
b = 2 100 : 12
b = 175
a = 300 - 175 = 125
Verificare:
125 + 175 = 300
a = 125
b = 175
