Exercice 1 :

1) 3x + 1 > 0

3x + 1 -1 > 0 - 1

3x ÷ 3 > -1 ÷ 3

x > [tex]\frac{-1}{3}[/tex]

2)  3x - (5x+7) ≥ 2x - 3

3x - (5x + 7) - 7 ≥ 2x - 3 - 7

3x - 5x - 2x ≥ 2x - 3 - 7 - 2x

-10x ≥ -10

[tex]\frac{-10x}{-10}[/tex] ≤ [tex]\frac{-10}{-10}[/tex]

x ≤ 1