Question

Determine o valor de x em cada proporção:

a) 3/x = 6/4
b) x/15 = 3/9
c) 7/3 = 14/x
d) 3x/18 = 6/4
e) x+2/8 = 6/4
f) 5/4 = x-2/x+4
g) x-2/x+3 = 4/8
h) 3/x = 2/18
i) 2/3 = x+4/2x-8

Answer 1

Explicação passo-a-passo:

Obs: nesses cálculos terá que fazer o cruz credo:

a) 3/x = 6/4

6.x = 3.4

6x = 12

x = 12/6

x = 2

b) x/15 = 3/9

x.9 = 15.3

9x = 45

x = 45/9

x = 5

c) 7/3 = 14/x

7.x = 14.3

7x = 42

x = 42/7

x = 6

d) 3x/18 = 6/4

3x . 4 = 18.6

12x = 108

x = 108/12

x = 9

e) x+2/8 = 6/4

(x + 2).4 = 8.6

4x + 8 = 48

4x = 48 - 8

4x = 40

x = 40/4

x = 10

f) 5/4 = x-2/x+4

5.(x + 4) = 4.( x - 2)

5x + 20 = 4x - 8

5x - 4x = - 8 - 20

x = - 28

g) x-2/x+3 = 4/8

(x -2).8 = (x + 3).4

8x - 16 = 4x + 12

8x - 4x = 12 + 16

4x = 28

x = 28/4

x = 7

h) 3/x = 2/18

3.18 = x.2

54 = 2x

2x = 54

x = 54/2

x = 27

i) 2/3 = x+4/2x-8

2.(2x - 8) = 3.(x + 4)

4x - 16 = 3x + 12

4x - 3x = 12 + 16

x = 28