Răspuns:
Explicație pas cu pas:
2 a + b + 2 c = 73
a + b + c = 57
______________ scad relatiile
a + c = 73 - 57
a + c = 16
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2 a + b + 2 c = 73 l × 2
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4 a + 2 b + 4 c = 146
a + c = 16
________________ adun relatiile
5 a + 2 b + 5 c = 162
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( a + c ) ( 5 a + 2 b + 5 c ) = 16 × 162 = 2592