Răspuns:
notam cu s =sandala,p=pantof , a=adidas
(d. p.) → (s-5)/2=(p-5)/3=(a-5)/5=k coeficient de proportionalitate
s=2k+5
p=3k+5
a=5k+5
(i. p.) → 25(p+5)=19(a+5)
25(3k+5+5)=19(5k+5+5)
75k+125+125=95k+95+95
250-190=95k-75k
60=20k=>k=60:20=>k=3
s=2k+5=6+5=11 ani
p=3k+5=9+5=14 ani
a=5k+5=15+5=20 ani
