Răspuns:
[tex]a) \frac{3}{7} = \frac{x \times 3}{x \times 7} \\ x \times 3 + x \times 7 = 30 \\ x \times 10 = 30 \\ x = 30 \div 10 \\ x = 3 \\ \frac{3 \times 3}{3 \times 7} = \frac{9}{21} \\ \\ b) \frac{3}{7} = \frac{x \times3 }{x \times 7} \\ x \times 7 - x \times 3 = 12 \\ x \times 4 = 12 \\ x = 12 \div 4 \\ x = 3 \\ \frac{3 \times 3}{3 \times 7} = \frac{9}{21} [/tex]
Sper ca te-am ajutat
