5a + 4b = 3a + 2a + 2b + 2b = 3a + 2b + 2a + 2b = 3a + 2b + 2(a+b) = 67 + 2*29 = 125
a+b=29|*2 2a+2b=58
3a+2b=67
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adunăm. 5a+4b=125