Question

quanto vale o:

a)1/7=x/21
b)4/5=12/x
c)5/7=x/42
d)x/4=15/20
e)21/35=x/4
f)12/48=x/4

Answer 1

Oi

Multiplique em cruzado.

a) 1/7 = x/21

7.x = 1.21

7x = 21

x = 21/7

x = 3

b) 4/5 = 12/x

4.x = 5.12

4x = 60

x = 60/4

x = 15

c) 5/7 = x/42

7.x = 5.42

7x = 210

x = 210/7

x = 30

d) x/4 = 15/20

20.x = 4.15

20x = 60

x = 60/20

x = 3

e) 21/35 = x/4

35.x = 21.4

35x = 84

x = 84/35 ÷ 7

x = 12/5

f) 12/48 = x/4

48.x = 12.4

48x = 48

x = 48/48

x = 1

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