Răspuns:
În casete!
Explicație pas cu pas:
[tex]\displaystyle \frac{1}{7}+\frac{3}{7}=\frac{1+3}{7}=\boxed{\frac{4}{7}}[/tex]
[tex]\displaystyle \frac{1}{7}+\frac{4}{7}=\frac{1+4}{7}=\boxed{\frac{5}{7}}[/tex]
[tex]\displaystyle \frac{1}{7}+\frac{2}{7}=\frac{1+2}{7}=\boxed{\frac{3}{7}}[/tex]
[tex]\displaystyle \frac{1}{7}+\frac{6}{7}=\frac{1+6}{7} =\frac{7}{7}=\boxed{1}[/tex]
[tex]\displaystyle \frac{1}{7}+\frac{5}{7}=\frac{1+5}{7}= \boxed{\frac{6}{7}}[/tex]