Resposta :
{-1+5.[2/3-5/7]-(1/2-3/4)-²}
{-1 + 5 . [ (14-15)/21]-((2-3)/4)^-2}
{- 1 + 5 . [-1/21] - (-1/4)^-2}
{ - 1 - 5/21 - 16}
{ ( - 21 - 5 - 336)/21 }
- 362/21
{-1 + 5 . [ (14-15)/21]-((2-3)/4)^-2}
{- 1 + 5 . [-1/21] - (-1/4)^-2}
{ - 1 - 5/21 - 16}
{ ( - 21 - 5 - 336)/21 }
- 362/21