Question

Me ajude a resolver a conta

Answer 1

Resposta:

a)

$\dfrac{x + 7}{4} = \dfrac{11 - x}{2} \\ \\ 4( 11 - x) = 2(x + 7) \\ \\ 44 - 4x = 2x + 7 \\ \\ 2x + 14 = 44 - 4x \\ \\ 4x + 2x = 44 - 14 \\ \\ 6x = 30 \\ \\ x = \dfrac{30}{6} \\ \\ \blue{x = 5}$

b)

$\dfrac{x + 3}{12 - x} = \dfrac{2}{3} \\ \\ 3(x + 3) = 2(12 - x) \\ \\ 3x + 9 = 24- 2x \\ \\ 3x + 2x = 24 - 9 \\ \\ 5x = 15 \\ \\ x = \dfrac{15}{5} \\ \\ \blue{x = 3}$

c)

$\dfrac{18}{x + 8} = \dfrac{2}{x} \\ \\ 18x = 2(x + 8) \\ \\ 18x = 2x + 16 \\ \\ 18 x - 2x = 16 \\ \\ 16x = 16 \\ \\ x = \dfrac{16}{16} \\ \\ \blue{ x = 1}$

d)

$\dfrac{2 - 2x}{3x} = - \dfrac{1}{3} \\ \\ 3(2 - 2x) = - 1(3x) \\ \\ 6 - 6x = - 3x \\ \\ - 3x = 6 - 6x \\ \\ 6x - 3x = 6 \\ \\ 3x = 6 \\ \\ x = \dfrac{6}{3} \\ \\ \blue{ x = 2}$

Bons Estudos!