Question

Calcule o valor de x nas proporções

A)15/30 = x/10

B)x+3/6 = 16/3

C)2x/7 = 14/8

D)20_x-2= 5/4

Answer 1

Vamos là.

A) 15/30 = x/10

30x = 150

x = 150/30

x = 5  

B) (x + 3)/6 = 16/3

(x + 3)/6 = 32/6

x + 3 = 32

x = 32 - 3 = 29  

C) 2x/7 = 14/8

16x = 7*14

x = 98/16 = 49/8  

D) 20/(x - 2) = 5/4

5*(x - 2) = 4*20

x - 2 = 4*4 = 16

x = 18

Answer 2

Explicação passo-a-passo:

A)

$\dfrac{15}{30} = \dfrac{x}{10}$

$30x = 15 \times 10$

$30x = 150$

$x = \dfrac{150}{30}$

X=5

B)

$\dfrac{x + 3}{6} = \dfrac{16}{3}$

$3(x + 3) = 6 \times 16$

$3x + 9 = 96$

$3x = 96 - 9$

$3x = 87$

$x = \dfrac{87}{3}$

X=29

C)

$\dfrac{2x}{7} = \dfrac{14}{8}$

$2x \times 8 = 14 \times 7$

$16x = 98$

$x = \dfrac{98 {}^{ \div 2} }{16 {}^{ \div 2} }$

x=49/8

D)

$\dfrac{20}{x - 2} = \dfrac{5}{4}$

$5(x - 2) = 20 \times 4$

$5x - 10 = 80$

$5x = 80 + 10$

$5x = 90$

$x = \dfrac{90}{5}$

x=18