Verified answer

a) 18

b) 5

C) 81

d) 4

e) 20

Espero ter ajudado

Resposta:

a) 18/20; b) 4/5; c) 1/5; d) 3/4; e) 20/30.

Explicação passo a passo:

a) 36/40 = x/20

40x = 36 . 20

40x = 720

x = 720 : 40

x = 18.

b) 20/25 = 4/x

20x = 25 . 4

20x = 100

x = 100 : 20

x = 5.

c) x/5 = 9/45

45x = 5 . 9

45x = 45

x = 45 : 45

x = 1.

d) 3/x = 75/100

75x = 3 . 100

75x = 300

x = 300 : 75

x = 4.

e) 2/3 = x/30

3x = 2 . 30

3x = 60

x = 60 : 3

x = 20.