3x-y/2=x-y/5 3x-y/2-x-y/5=0 aducem la acelasi numitor amplificam prima cu 5 si a doua cu 2 15x-5y/10-2x-2y/10=0 15x-5y-2x-2y/10=0 13x-7y/10=0 inmultim cu 10 prin metoda balantei 13x-7y=0 13x=7y x=7y/13 doar atat daca stiai cat e y sau x era un raspuns concret
