Resposta :
[tex]b) \ (\frac{3}{5} + \frac{2}{5}) \cdot 30 = \frac{5}{5} \cdot 30 = 1 \cdot 30 = 30 \\\\ c) \ \frac{1}{5} + \frac{1}{8} = \frac{8}{40} + \frac{5}{40} = \frac{13}{40} \\\\ d) \ \frac{1}{2} - \frac{1}{8} = \frac{4}{8} - \frac{1}{8} = \frac{3}{8} \\\\ e) \ -\frac{2}{3} \cdot \frac{9}{8} = -\frac{18}{24} = -\frac{3}{4} \\\\ f) \ (\frac{8}{3} + \frac{7}{6}) \cdot (\frac{1}{3} - \frac{1}{2}) = (\frac{16}{6} + \frac{7}{6}) \cdot (\frac{2}{6} + \frac{3}{6}) = \frac{23}{6} \cdot \frac{5}{6} = \frac{115}{36}[/tex]
[tex]g) \ (-\frac{1}{3})^2 : (-\frac{5}{6}) = \frac{1}{9} : (-\frac{5}{6}) = \frac{1}{9} \cdot (-\frac{5}{6}) = -\frac{5}{54}[/tex]
[tex]g) \ (-\frac{1}{3})^2 : (-\frac{5}{6}) = \frac{1}{9} : (-\frac{5}{6}) = \frac{1}{9} \cdot (-\frac{5}{6}) = -\frac{5}{54}[/tex]