Răspuns :
5a = 2b b = 5a/2
axb = ax5a/2 = 40
5a² = 80 a² = 16 a = 4 b = 10
axb = ax5a/2 = 40
5a² = 80 a² = 16 a = 4 b = 10
5a=2b=k => a=k/5 si b=k/2. Dar a×b=40 => k patrat/10=40 => k patrat=400 => k=20 deci a=4 si b=10