[tex]2x^{2}-4x<30\\2x^{2}-4-30<0\\x^{2}-2x-15<0\\x^{2}+3x-5x-15<0\\x(x+3)-5(x+3)<0\\(x+3)(x-5)<0\\\left \{ {{x+3<0} \atop {x-5>0}} \right. \\\left \{ {{x+3>0} \atop {x-5<0}} \right. \\\left \{ {{x<-3} \atop {x>5}} \right. \\\left \{ {{x>-3} \atop {x<5}} \right. \\[/tex]
x∈∅
x∈<-3,5>
Mam nadzieję, że pomogłam :)
