Resposta:
Explicação passo a passo:
[tex]a) 7^{3} - 49 + 5^{2} = 343 - 49 + 25 = 294 + 25 = 319\\[/tex]
[tex]b) (-8)^{3} : (-2) + 3 . (-4)^{3} = - 512 : (- 2) + 3 . (-64) = 256 - 192 = 256 - 192 = 64\\[/tex]
[tex]c) 5^{-3} - (-\frac{1}{5}) ^{2} = -\frac{1}{5} - \frac{1}{25} = \frac{-5-1}{25} = -\frac{6}{25} \\[/tex]
[tex]d) (\frac{2}{3}) ^{-2} - (\frac{2}{5}) ^{-3} = (\frac{3}{2}) ^{2} - (\frac{5}{2}) ^{3} = \frac{9}{4} - \frac{125}{8} = \frac{18 - 125}{8} = -\frac{117}{8} \\[/tex]
[tex]e) (2 - \frac{3}{4})^{2} + (- \frac{1}{4}) ^{2} = (\frac{8 - 3}{4}) ^{2} + \frac{1}{16} = (\frac{5}{4}) ^{2} + \frac{1}{16} = \frac{25}{16} + \frac{1}{16} = \frac{26}{16} : 2 = \frac{13}{8}[/tex]
