1) Aflam cit a realizat in a doua zi :
[tex] \frac{1}{17} + \frac{4}{17}= \frac{5}{17} [/tex]
2) Adunam cit a facut in cele doua zile :
[tex] \frac{4}{17} + \frac{5}{17} = \frac{9}{17} [/tex]
3) Scadem din totalul de lucru,cit a lucrat muncitorul timp de cele doua zile :
[tex] \frac{17}{17} - \frac{9}{17} = \frac{8}{17} [/tex]