Răspunsuri

2014-06-11T20:36:11+03:00
28=b+f
24=b-4+3(b-4)
24=b-4+3b-12=4b-16
24+16=40=4b ⇒ b=40:4=10
⇒f=28-10=18
verificare b-4=6 ⇒ 18=3*6=18
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