Resposta:

[tex]a) \: 3 \times (x + 2) \leqslant 2 \times (2x + 4) \\ 3x + 6 \leqslant 4x + 8 \\ 3x + 6 - 4x \leqslant 8 \\ 3x - 4x \leqslant 8 - 6 \\ - x \leqslant 2 \times ( - 1) \\ x \geqslant - 2[/tex]

[tex]b) \: \frac{x + 4}{3} - \frac{3x + 2}{4} \geqslant 0 \\ \\ \frac{4 \times (x + 4) - 3 \times (3x + 2)}{12} \geqslant 0 \\ \\ 4 \times (x + 4) - 3 \times (3x + 2) \geqslant 0 \\ 4x + 16 - 9x - 6 \geqslant 0 \\ - 5x + 10 \geqslant 0 \\ - 5x \geqslant - 10 \div ( - 5) \\ x \leqslant 2[/tex]

[tex]c) \: 4x - 5 \times (x - 2) > x + 6 \\ 4x - 5x + 10 > x + 6 \\ - x + 10 > x + 6 \\ - x + 10 - x > 6 \\ - x - x > 6 - 10 \\ - 2x > - 4 \div ( - 2) \\ x < 2[/tex]

[tex]2.a) \: 5x - 27 = - 4x \\ 5x - 27 + 4x = 0 \\ 5x + 4x = 27 \\ 9x = 27 \\ \\ x = \frac{27}{9} \\ \\ x = 3[/tex]

[tex]b) \: 7y + 11 = 15 + 5y \\ 7y + 11 - 5y = 15 \\ 7y - 5y = 15 - 11 \\ 2y = 4 \\ \\ y = \frac{4}{2} \\ \\ y = 2[/tex]

[tex]c) \: \frac{5x}{2} = 2x + \frac{ x- 2}{3} \\ \\ \frac{15x = 12x + 2 \times (x - 2)}{6} \\ \\ 15x = 12x + 2x - 4 \\ 15x =14x - 4 \\ 15x - 14x = - 4 \\ x = - 4[/tex]