Question

(20 pontos)

Resolva as INEQUAÇÕES sendo U = N

$2x + 10 < 20$
$7x + 2 > 79$
$4x + 2x - 2 > x + 3$
$2 \: (x + 1) \: + 5 < 9$
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Answer 1

Explicação passo-a-passo:

a)

$\sf 2x+10 < 20$

$\sf 2x < 20-10$

$\sf 2x < 10$

$\sf x < \dfrac{10}{2}$

$\sf x < 5$

$\sf \red{S=\{0,1,2,3,4\}}$

b)

$\sf 7x+2 < 79$

$\sf 7x < 79-2$

$\sf 7x > 77$

$\sf x > \dfrac{77}{7}$

$\sf x > 11$

$\sf \red{S=\{12,13,14,15,...\}}$

c)

$\sf 4x+2x-2 > x+3$

$\sf 4x+2x-x > 3+2$

$\sf 5x > 5$

$\sf x > \dfrac{5}{5}$

$\sf x > 1$

$\sf \red{S=\{2,3,4,5,...\}}$

d)

$\sf 2\cdot(x+1)+5 < 9$

$\sf 2x+2+5 < 9$

$\sf 2x < 9-5-2$

$\sf 2x < 2$

$\sf x < \dfrac{2}{2}$

$\sf x < 1$

$\sf \red{S=\{0\}}$