Question

найдите все k при которых 3k-7 < 6-k < 2k+2

Answer 1

$3k-7 \ \textless \ 6-k \ \textless \ 2k+2$

$\left \{ {{6-k \ \textgreater \ 3k-7} \atop {6-k \ \textless \ 2k+2}} \right.$

$\left \{ {{-4k \ \textgreater \ -13} \atop {-3k \ \textless \ -4}} \right.$

$\left \{ {{k \ \textless \ \frac{13}{4} } \atop {k \ \textgreater \ \frac{4}{3} }} \right.$

Ответ: k ∈ $( \frac{4}{3} ; \frac{13}{4} )$