Răspuns :
Răspuns:
11 .
(a,b) d.p (2,7) => a=2k , b=7k
3a+2b=420
3*2k+2*7k=420 => 20k=420 => k=420/20 => k=21
a=2*21 =>a=42
b=7*21 =>b=147
12 .
(a,b) d.p (3,5) => a=3k , b=5k
b-a=36,4 => 5k-3k=36,4 => 2k=36,4 =>k=18,2
a=3*18,2 => a=54,6
b=5*18,2 => b=91