Răspuns:
Explicație pas cu pas:
[tex]a+b+c=1-\frac{1}{2}+1-\frac{2}{3}+1-\frac{5}{6}=3-\frac{3+4+5}{6}=3-\frac{12}{6}=3-2=1\\\\a-b+c= 1-\frac{1}{2}-1+\frac{2}{3}+1-\frac{5}{6} =1+\frac{-3+4-5}{6}=1-\frac{4}{6}=1- \frac{2}{3}=\frac{1}{3}\\\\a+b-c=1-\frac{1}{2}+1-\frac{2}{3}-1+\frac{5}{6}=1+\frac{-3-3+5}{6}=1-\frac{1}{6}=\frac{5}{6}\\\\a-b-c=1-\frac{1}{2}-1+\frac{2}{3}-1+\frac{5}{6}=-1+\frac{-3+4+5}{6} =-1+1=0[/tex]
