Question

Решите неравенство ( с подробным решением)
-x^2+11х+12 < 0

Answer 1

$\displaystyle\bf\\-x^{2} +11x+12<0\\\\x^{2} -11x-12>0\\\\x^{2} -12x+x-12>0\\\\(x^{2} -12x)+(x-12)>0\\\\x(x-12)+(x-12)>0\\\\(x-12)(x+1)>0$

+ + + + + (- 1) - - - - - (12) + + + + +

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$\displaystyle\bf\\Otvet:x\in\Big(-\infty \ ; \ -1\Big) \ \cup \ \Big(12 \ ; \ \+\infty\Big)$