Question

5к²-7 к+2<0 решите неравенство

Answer 1

я возьму к как х 
5$x^{2}$-7x+2<0
5$x^{2}$-2x-5x+2<0
x(5x-2)-(5x-2)<0
(x-1)(5x-2)<0
рассматриваем два случая:
$1) left { {{x-1 textless 0} atop {5x-2 textgreater 0}} right. = left { {{x<1} atop {x >frac{2}{5} }} right.$
$2) left { {{x-1 textgreater 0} atop {5x-2 textless 0}} right. = left { {{x textgreater 1} atop {x textless frac{2}{5} }} right.$
1) x∈($frac{2}{5}$;1)
2) x∉∅