Răspunsuri

2014-10-11T17:45:59+03:00
(a+4):7=(a-9):66*(a+4) = 7*(a-9)
6a+24=7a-63
24+63=7a-6a
87=a

VERIFICARE:
(87+4):7 = (87-9):6
91:7=78:6
13=13 ADEVARAT
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