คู่มือผู้ใช้



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



 RATIO 

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 

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

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 

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







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

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 

 RATIO

 1:  X  1 : 2 = X : 10

(RATIO)

(a:b=X:d) 1 2 10

 2: 

 X  1 : 2 = 10 : X

(RATIO)

(a:b=c:X) 1 2 10