Explicație pas cu pas:
[tex] \frac{2}{2} + ( - \frac{7 }{5} ) - ( - \frac{1}{15} ) = \\ \\ = 1 - \frac{7}{15} + \frac{1}{15} = \frac{15 - 21 + 1}{15} = \\ \\ = - \frac{5}{15 } = - \frac{1}{3} [/tex]
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[tex] - \frac{1}{7} + ( - \frac{ 3}{14} ) - ( - \frac{1}{2} ) = \\ \\ = - \frac{1}{7} - \frac{3}{14} + \frac{1}{2} = \frac{ - 2 - 3 + 7}{14} = \\ \\ = \frac{2}{14} = \frac{1}{7} [/tex]
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[tex] \frac{1}{6} - ( - \frac{1}{4} ) + \frac{5}{12} - ( + \frac{7}{3} ) = \\ \\ \frac{1}{6} + \frac{1}{4} + \frac{5}{12} - \frac{7}{3} = \frac{2 + 3 + 5 - 28}{12} = \\ \\ = - \frac{18}{12} = - \frac{3}{2} [/tex]
