Explicație pas cu pas:
[tex] \frac{1}{5} + ( - \frac{1}{5} ) = 0[/tex]
[tex]( - \frac{7}{3} ) + ( + \frac{5}{3} ) = - \frac{2}{3} [/tex]
[tex] \frac{11}{4} - ( - \frac{1}{4} ) = \frac{11}{4} + \frac{1}{4} = \frac{12}{4} = 3[/tex]
[tex] - \frac{2}{5 } + ( - \frac{7}{5} ) = - \frac{2 }{5} - \frac{7}{5} = - \frac{9}{5} [/tex]
