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. \\" alt="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. \\" align="absmiddle" class="latex-formula">
x ∈ ⟨3,+∞ ⟩
x ∈ ⟨-∞, -5⟩
x ∈ ⟨-∞, -5⟩ ∪ ⟨3,+∞ ⟩
Ответ: x ∈ ⟨-∞, -5⟩ ∪ ⟨3,+∞ ⟩