Question

Решите эти 3 неравенства, пожалуйста

Answer 1

25$x^{2}$-4(8-5x)<80x-64
25$x^{2}$-32+20x<80x-64
25$x^{2}$-32+20x-80x+64<0
25$x^{2}$+32-60x<0
25$x^{2}$-60x+32<0
25$x^{2}$-20x-40x+32<0
5x(5x-4)-8(5x-4)<0
(5x-8)(5x-4)<0
$\left \{ {{5x-8\ \textless \ 0} \atop {5x-4\ \textgreater \ 0}} \right.$
$\left \{ {{5x-8\ \textgreater \ 0} \atop {5x-4\ \textless \ 0}} \right.$
$\left \{ {{x\ \textless \ \frac{8}{5} } \atop {x\ \textgreater \ \frac{4}{5} }} \right.$
$\left \{ {{x\ \textgreater \ \frac{8}{5} } \atop {x\ \textless \ \frac{4}{5} }} \right.$
x∈($\frac{4}{5}$, $\frac{8}{5}$)
x∈∅
x∈($\frac{4}{5}$, $\frac{8}{5}$)