Question

${ \times }^{2} + 2 \times - 15 > 0$
​ помогите пожалуйста КН!!!

Answer 1

$x^{2} +2x-3x>0\\x^{2} +5x-3x-15>0\\x(x+5)-3(x+5)>0\\(x+5)(x-3)>0\\\left \{ {{x+5>0} \atop {x-3>0}} \right.\\\left \{ {{x+5<0} \atop {x-3<0}} \right. \\\left \{ {{x>-5} \atop {x>3}} \right.\\\left \{ {{x<-5} \atop {x<3}} \right.$

x  ∈  ⟨3,+∞ ⟩

x ∈  ⟨-∞, -5⟩

x ∈  ⟨-∞, -5⟩ ∪ ⟨3,+∞ ⟩

Ответ:  x ∈  ⟨-∞, -5⟩ ∪ ⟨3,+∞ ⟩