Question

$2x+13 \geq 9,sendo U=Z$

Answer 1

vamos lá...

$2x+13 \geq 9 \\ \\ 2x \geq 9-13 \\ \\ 2x \geq -4 \\ \\ x \geq -4\div2 \\ \\ x \geq -2$

S={ x ∈ Z / x ≥ -2}