∅ Rezolvare :
Datele problemei :
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x + z = 200
170 + 160 + 150 = 480 ( studenți )
1x +3z = 480 →
x = 480 - 3z →
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x + z = 200 →
480 - 3z + z = 200 → 3z - z = 480 - 200 →
2z = 280 →
z = 280 : 2 →
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z = 140
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↓
x + 140 = 200 →
x = 200 - 140 →
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x = 60
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↓
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- 60 de studenți vorbesc o singură limbă
- 140 de studenți vorbesc toate cele 3 limbi .
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