Răspuns:
[tex]a=\frac{1}{2}+\frac{2}{3}+\frac{3}{4}+\frac{4}{5}[/tex]
[tex]b=\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+\frac{1}{5}[/tex]
[tex]a+b=\frac{1}{2}+\frac{2}{3}+\frac{3}{4}+\frac{4}{5}+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+\frac{1}{5}=\frac{1}{2}+\frac{1}{2}+\frac{2}{3}+\frac{1}{3}+\frac{3}{4}+\frac{1}{4}+\frac{4}{5}+\frac{1}{5}=1+1+1+1=4[/tex]
Explicație pas cu pas:
