III. Calcule o valor das seguintes expressões:
a) 15-(3-2) + (-7+4)
b) 18.12 + (7-3-8) - 101
c) -4+ [- 3+ ( -5 + 9 - 2)]
d) 25 - {- 2 + 16 + (-4-1)}
e) { 30+ [10 - 5+(-2-3)1-18-12}
f) - {-2-1-3.(-5)+1]}

[tex] \sf18 \times 12 + (7 - 3 - 8) - 101 \\ \sf216 + (- 4) - 101 \\ \sf216 - 4 - 101 \\ \sf216 - 105 \\\large\boxed{{\sf \blue1 \blue1 \blue1{}}} [/tex]

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[tex]\large\boxed{{\sf Letra ~\red{C}}}[/tex]

[tex] \sf - 4 + [ - 3 + ( - 5 + 9 - 2)] \\ \sf - 4 + [ - 3 + 2] \\ \sf - 4 + [ - 1] \\ \sf - 4 - 1 \\ \large\boxed{{\sf \red - \red5{}}}[/tex]

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[tex]\large\boxed{{\sf Letra ~\green{D}}}[/tex]

[tex]\sf25 - [ - 2 + 16 + ( - 4 - 1)] \\ \sf25 - [ - 2 + 16 + ( -5)] \\ \sf25 - [ - 2 + 16 - 5] \\ \sf25 - [ - 2 + 16 - 5] \\ \sf25 - 7 + 16 \\ \sf25 - 9 \\ \large\boxed{{\sf \green1 \green6{}}}[/tex]

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[tex]\large\boxed{{\sf Letra ~\orange{E}}}[/tex]

[tex] \sf [30 + [10 - 5 + ( - 2 - 3)] 1 - 18 - 12] \\ \sf [30 + [10 - 5 + ( - 5)] - 18 - 12] \\\sf [30 + [10 - 5 - 5] - 18 - 12] \\ \sf [30 + 0 - 18 - 12] \\ \sf [30 - 18 - 12] \\ \sf30 - 30 \\ \sf\large\boxed{{\sf \orange0{}}}[/tex]

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[tex]\large\boxed{{\sf Letra ~\purple{F}}}[/tex]

[tex] \sf - [ - 2 - 1 - 3 \times ( - 5) + 1] \\ \sf - [ - 2 - 3 \times ( - 5)] \\ \sf - [ - 2 + 15] \\ \large\boxed{{\sf \purple- \purple1 \purple3 {}}}[/tex]