Răspuns:
tr.ANM~tr.ACB
AN/AC=AM/AB=NM/CB
(3x+1)/(3x+1+14) = (x+1)/(x+1+5)
(3x+1)/(3x+15) = (x+1)/(x+6)
(3x+15)(x+1)=(3x+1)(x+6)
3x^2 + 18x + 15 = 3x^2 + 19x + 6
x=9 =>AM=10 cm =>AB=15 cm
AN=28 cm =>AC=42 cm
AN/AC=28/42=2/3=Aria ANM/Aria ACB
