Resposta:
2)
[tex]a) \: 2x - 27 = 5x \\ \\ 2x - 5x = 27 \\ \\ - 3x = 27 ( - 1)\\ \\ 3x = - 27 \\ \\ x = - \dfrac{27}{3} \\ \\ \blue{x = - 9}[/tex]
[tex]b) \: \dfrac{x - 4}{8} = \dfrac{x}{5} \\ \\ 8x = 5(x - 4) \\ \\ 8x = 5x - 20 \\ \\ 8x - 5x = -20 \\ \\ 3x = -20 \\ \\\blue{ x = -\dfrac{20}{3} }[/tex]
[tex]c) \: 0.2x - 5 = 10 - 0.3x \\ \\ 0,2x + 0,3x = 10 + 5 \\ \\ 0,5x = 15 \\ \\ \dfrac{x}{2} = 15 \\ \\ x = 2 \times 15 \\ \\\blue{ x = 30}[/tex]
[tex]5) \: a) \: \dfrac{20}{4} = \dfrac{x}{2} \\ \\ 5 = \dfrac{x}{2} \\ \\ x = 2 \times 5 \\ \\\blue{ x = 10}[/tex]
[tex]b) \: \dfrac{4}{x} = \dfrac{8}{10} \\ \\ 8x = 4 \times 10 \\ \\ 8x = 40 \\ \\ x = \dfrac{40}{8} \\ \\\blue{ x = 5}[/tex]
[tex]c) \: \dfrac{x}{3} = \dfrac{2}{6} \\ \\ 6x = 2 \times 3 \\ \\ 6x = 6 \\ \\ x = \dfrac{6}{6} \\ \\ \blue{ x = 1}[/tex]
[tex]d) \: \dfrac{4}{30} = \dfrac{8}{x} \\ \\ 4x = 8 \times 30 \\ \\ 4x = 240 \\ \\ \blue{x = 60}[/tex]
Bons Estudos!
