1) \(-18-x=-12\Rightarrow x=-6\rightarrow D\)
2. \(x\in\left\{-4;-3;-2;-1;0;1;2;3;4;5\right\}\rightarrow A\)
-18 - x = 12
x = -18 - 12
x = -30
Chọn B
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-5 < x 5
x {-4; -3; -2; -1; 0; 1; 2; 3; 4; 5}
Tổng là:
(-4) + (-3) + (-2) + ... + 4 + 5
= 5
Chọn A