Explicação passo-a-passo:
[tex]a)( - \frac{2}{3} ) {}^{2} + ( - \frac{2}{3} ) + ( - \frac{2}{3} ) {}^{0} = \frac{4}{9} - \frac{2}{3} + 1 = [/tex]
[tex]m.m.c = 9[/tex]
[tex] \frac{4 - 6 + 9}{9} = \frac{7}{9} [/tex]
[tex]b)(2 - \frac{1}{4} ) - (3 - \frac{1}{2} ) = ( \frac{8 - 1}{4} ) - ( \frac{6 - 1}{2} ) = \frac{7}{4 } - \frac{5}{2} = m.m.c = 4[/tex]
[tex] \frac{7 - 10}{4} = \frac{ - 3}{4} [/tex]
[tex]c)( \frac{3}{4} - \frac{5}{6} ) \div ( \frac{1}{2} + \frac{1}{4} ) = ( \frac{18 - 20}{24} ) \div ( \frac{2 + 1}{4} ) = [/tex]
[tex] \frac{ - 2}{24} \div \frac{3}{4} = \frac{ - 2}{24} \times \frac{4}{3} = \frac{ - 8}{72} = \frac{ - 1}{9} [/tex]
[tex]d)( - 1 + \frac{1}{2} ).( - 2 - \frac{3}{4} ) = ( \frac{ - 2 + 1}{2} ).( \frac{ - 8 - 3}{4} ) = \frac{ - 1}{2} . \frac{ - 11}{4} = + \frac{11}{8} [/tex]
