Răspuns:
Explicație pas cu pas:
(1/21+1/14)-(1/35-1/42)+(1/14-1/21)=
(²⁾ 1/21+³⁾1/14 )-(⁶⁾1/35-⁵⁾1/42 ) +(³⁾1/14- ²⁾1/21) =
(2+3 )/42 - (6-5) / 210 + (3-2) /42=
⁵⁾5/42- 1/210 +⁵⁾1/42=
25/210- 1/210 +5 /210=
24/210+5/210=
29/210
