Notăm:
d = dischetele Dianei
v = dischetele lui Victor
d = 9v
d-3 = 4(v+3)
=> d-3 = 4v + 12
=> d-4v = 12+3
=> d-4v = 15
=> d = 15+4v
15+4v = 9v
=> 15 = 9v-4v
=> 15 = 5v
=> v = 3
=> d = 9*3 = 27
Răspuns: Diana are 27 de dischete, iar Victor 3 dischete.
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