Cameron's uncle is 3 times old as he is. 4 years ago, he was 4 times older. how old is cameron?

Let Cameron be x years old now.

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Now:

Cameron = x

Uncle =3x

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4 years ago:

Cameron = x - 4

Uncle = 3x - 4

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4 years ago, Uncle is 4 times older:

3x - 4 = 4(x - 4)

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Find x:

3x - 4 = 4(x - 4)

3x - 4 = 4x - 16

4x - 3x = 16 - 4

x = 12

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Find the age:

Cameron = x = 12

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Cameron is 12 years old now.

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional