Question

$(x + 1) (x - 2) > 0$
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Answer 1

Метод интервалов.

$(x+1)(x-2)>0\\\\x+1=0\; \; \to \; \; x_1=-1\\\\x-2=0\; \; \to \; \; x_2=2\\\\znaki:\; \; \; \; +++(-1)---(2)+++\\\\x\in (-\infty ,-1)\cup (2,+\infty )$