Question

determine o valor do termo desconhecido:

a) 1 / 4 = x+3 / 20

b) 2 / 9 = x+1 / 18

c) 2 / x+1 = 1 / 5

d) 5 / x-3 = 2 / 8

((são frações))

Answer 1

a) 1/4 = (x + 3)/20

1 = (4x + 12)/20

20 = 4x + 12

8 = 4x

2 = x

x = 2.

b) 2/9 = (x + 1)/18

2 = (9x + 9)/18

36 = 9x + 9

27 = 9x

3 = x

x = 3.

c) 2/(x + 1) = 1/5

2 = (x + 1)/5

10 = x + 1

9 = x

x = 9.

d) 5/(x - 3) = 2/8

5 = (2x - 6)/8

40 = 2x - 6

46 = 2x

23 = x

x = 23.

:)