Question

Qual o valor da inequação : 3x+9 > 12 ?

Answer 1

$3x+9\ \textgreater \ 12\to \\\\ 3x\ \textgreater \ 12-9\to \\\\ 3x\ \textgreater \ 3\to \\\\ x\ \textgreater \ \dfrac{3}{3} \to \\\\ x\ \textgreater \ 1\\\\\\\\\boxed{\boxed{S = \{x \epsilon \mathbb{R} \ | \ x\ \textgreater \ 1}}$

Answer 2

3x+9>12
3x>12-9
3x>3
x>3/3
x>1