Resposta:
[tex]1 - [\frac{-2}{5} -(\frac{-1}{2} +\frac{3}{4} )]\\\\1 - [\frac{-2}{5} -(\frac{-2 +3}{4})]\\\\1 - [\frac{-2}{5} - \frac{1}{4}]\\\\1 - [ \frac{-8 -5}{20}]\\\\1 - (\frac{-13}{20})\\\\1 +\frac{13}{20}\\\\\frac{33}{20}[/tex]
