a + b + c = 25
2a + b + 2c = 57
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adunate a + b +c + 2a + b +2c = 25 + 57
3a + 2b + 3c = 82
din a +b + c = 25 ; b = 25 - a -c
2a + ( 25 - a -c) + 2c = 57 ; 2a + 25 - a - c + 2c = 57
a + c = 57 - 25
a +c = 32
( a + c ) · ( 3a + 2b + 3c) = 32 · 82=2624