Question

B={x/X €Z; -7 <4x+1 <21} ayuda por favor

Answer 1

-7 < 4x + 1 < 21

-7<4x +1
-8<4x
-2<X

4x+1<21
4x<20
x<5

Entonces
-2<x<5

C.S= {-1;4}

Answer 2

$Hola \\ \\ B=\{x/x \in \mathbb{Z};-7\ \textless \ 4x+1\ \textless \ 21\} \\ \\ -7\ \textless \ 4x+1\ \textless \ 21 \\ \\ -7\ \textless \ 4x+1~~~~~~~~y~~~~~~~~4x+1\ \textless \ 21 \\ \\ -7-1\ \textless \ 4x~~~~~~~~~~~~~~~~~~4x\ \textless \ 21-1 \\ \\ -8\ \textless \ 4x~~~~~~~~~~~~~~~~~~~~~~~4x\ \textless \ 20 \\ \\ -2\ \textless \ x~~~~~~~~~~~~~~~~~~~~~~~~~~x\ \textless \ 5 \\ \\ B=\{x/x \in~\mathbb{Z}; -2\ \textless \ x\ \textless \ 5\}~--\ \textgreater \ : \\ \\ C.S=]-2;5[ \\ \\ \mathbb{iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii}\\~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Saludos!!$