Question

Resolva a inequação
3x+4>-2


resolva o sistema
$\left \{ {2x+3y=47} \atop {x-y=1}} \right.$

Answer 1

3x >-2-4
3x<-6
x<-6/3
x<-2

sistema
2x+3y=47
x-y=1
x=1+y  dai agora é substituir na primeira e ver o resultado ok
2(1+y)+3y=47
2+2y+3y=47
5y=47-2
5y=45
y= 45/5
y= 9  agora que achamos o x vamos substituir na segunda e achar o y
x-9=1
x=1+9
x=10

ok

agora , avalie-me

Answer 2

$3x+4\ \textgreater \ -2 \to~~ 3x\ \textgreater \ -2-4\to~~3x\ \textgreater \ -6\to~~x\ \textgreater \ - \dfrac{6}{3} \to~~ x\ \textgreater \ -2\\\\\\ \boxed{\boxed{S = \{x \epsilon \mathbb{R} \ | \ x\ \textgreater \ -2}}$




$\begin{cases}2x+3y=47\\ x-y=1\end{cases}\\\\\\ x-y=1\to~~x=y+1\\\\\\ 2x+3y=47\to~~2(y+1)+3y=47\to~~ 2y+2+3y=47\to\\\\ 2y+3y=47-2\to~~ 5y=45\to~~ y= \dfrac{45}{5} \to~~ \boxed{y=9}\\\\\\x=y+1\to~~ x=9+1\to~~\boxed{x=10}\\\\\\\\\\ \large\boxed{\boxed{S=\{10~;~9\}}}$