Question

Determine o valor de x nas proporções abaixo: (apresentar cálculos)

Por favor, me ajudem!​

Answer 1

Oie, Td Bom?!

c)

[3x - 1]/[x + 4] = 2/3

[3(3x - 1)]/[x + 4] = 2

3(3x - 1) = 2(x + 4)

9x - 3 = 2x + 8

9x - 2x = 8 + 3

7x = 11

x = 11/7

d)

[x + 5]/3 = [x - 1]/5

[5(x + 5)]/3 = x - 1

5(x + 5) = 3(x - 1)

5x + 25 = 3x - 3

5x - 3x = - 3 - 25

2x = - 28

x = - 28/2

x = - 14

Att. Makaveli1996

Answer 2

Explicação passo-a-passo:

C)

$\dfrac{3x - 1}{x + 4} = \dfrac{2}{3}$

$2(x + 4) = 3(3x - 1)$

$2x + 8 = 9x - 3$

$2x - 9x = - 3 - 8$

$- 7x = - 11( - 1)$

$7x = 11$

x=>11/7

D)

$\dfrac{x + 5}{3} = \dfrac{x - 1}{5}$

$3(x - 1) = 5(x + 5)$

$3x - 3 = 5x + 25$

$3x - 5x = 25 + 3$

$- 2x = 28$

$x = -\dfrac{28}{2}$

x=>-14