Răspuns :
daca a=|--|--|
b=|--|--|--|--|
c=|--|
a+b+c = 7*|--|=21 => c = |--|=21:7=3 .
b = 4*3=12 ,
a = 2*3=6 ,
a + b + c = 21
b = 2 × a = 2 × 2 c = 4 × c
a = 2 × c
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a + b + c = 21
2 × c + 4 × c + c = 21
7 × c = 21
c = 21 : 7
c = 3
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a = 2 × 3 ⇒ a = 6
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b = 2 × 6 ⇒ b = 12
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a × b × c = 6 × 12 × 3 = 72 × 3 = 216 → produsul numerelor