Explicație pas cu pas:
[tex]x = (1 + \frac{1}{2} + \frac{1}{4} ) \div \frac{7}{12} = \frac{4 + 2 + 1}{4} \div \frac{7}{12} = \frac{7}{4} \div \frac{7}{12} = \frac{7}{4} \times \frac{12}{7} = 3 \\ \\ y = (1 - \frac{1}{2} - \frac{1}{4} ) \div \frac{1}{4} = \frac{4 - 2 - 1}{4} \div \frac{1}{4} = \frac{1}{4} \div \frac{1}{4} = \frac{1}{4} \times \frac{4}{1} = 1 \\ \\ ma = \frac{3 + 1}{2} = \frac{4}{2} = 2[/tex]