Question

Найдите количество целых решений системы неравенств:
16(1-0,25x)<x 5(1+0,6x)<21

Answer 1

$\left \{ {{16(1-0,25x)\ \textless \ x} \atop {5(1+0,6x)\ \textless \ 21}} \right.\\\\ \left \{ {{16-4x\ \textless \ x} \atop {5+3x\ \textless \ 21}} \right.\\\\ \left \{ {{-4x-x\ \textless \ -16} \atop {3x\ \textless \ 21-5}} \right.\\\\ \left \{ {{-5x\ \textless \ -16} \atop {3x\ \textless \ 16}} \right.\\\\ \left \{ {{x\ \textgreater \ 3,2} \atop {x\ \textless \ 5 \frac{1}{3} }} \right.$
x ∈ (3,2 ; 5 1/3)
Два целых решения - это 4 и 5.